Neutral Citation Number: [2007] EWCA Civ 498
Case No: C1/2006/1465
IN THE SUPREME COURT OF JUDICATURE
COURT OF APPEAL (CIVIL DIVISION)
ON APPEAL FROM THE DIVISIONAL COURT
(LORD JUSTICE HOOPER and MR JUSTICE CRESSWELL)
[2006] EWHC 1038 (ADMIN)
Royal Courts of Justice
Strand, London, WC2A 2LL

23/05/2007
Before:

THE MASTER OF THE ROLLS
LORD JUSTICE WALLER
Vice-President of the Court of Appeal, Civil Division
and
LORD JUSTICE SEDLEY
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Between :

	 SECRETARY OF STATE FOR THE FOREIGN AND COMMONWEALTH AFFAIRS	Appellant Defendant/ 	
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	THE QUEEN (ON THE APPLICATION OF BANCOULT)	Respondent Claimant/ 	
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(Transcript of the Handed Down Judgment of
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Mr J Howell QC and Mr K Beal (instructed by The Treasury Solicitor) for the Appellant
Sir Sydney Kentridge QC, Mr A Bradley and Ms M Lester (instructed by Messrs Sheridans) for the Respondent

Hearing dates: 5th-7th February and 13th-16th February 2007 
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Judgment
Lord Justice Sedley : 

INDEX.

A short history	paras. 2. – 13	
The constitutional issues	paras. 14 – 47	
 (1) The Colonial Laws Validity Act 1865	paras. 15 – 30	
 (2) Sovereign Power	paras. 31 – 47 	
The public law issues	paras. 48 – 49	
The objects of colonial governance	paras. 50 – 71	
Legitimate expectation	paras. 72 – 77	
Conclusion	paras. 78 - 79	

1.	This appeal comes before the court by permission of the Divisional Court (Hooper LJ and Cresswell J) which decided the case at first instance. Their decision, in brief, was that the provisions of the Orders in Council by which the Crown in 2004 had forbidden the return of the Chagossians to the islands which they or their forebears had inhabited were invalid. Mr John Howell QC on behalf of the Secretary of State for Foreign and Commonwealth Affairs challenges the decision. Sir Sydney Kentridge QC on behalf of the representative claimant Mr Bancoult supports it on the Divisional Court’s grounds and on further grounds. The case raises issues of constitutional importance. They have been canvassed in extensive submissions which, unavoidably, will have to be selectively addressed. 

A short history

2.	The Chagos Islands were ceded to Great Britain, together with Mauritius and certain other Indian Ocean dependencies, by France in 1814. In 1965 the Chagos Islands (and some other islands, later severed) were constituted a separate colony, the British Indian Ocean Territory (BIOT). Such dependencies are ordinarily governed by or under Orders in Council made in the exercise of the prerogative power of the Crown. 
3.	The exiling of the Chagossian population by the use of prerogative powers in the 1960s and 1970s has been recounted in detail several times in the course of the litigation which is described below. It can be found in paragraphs 6 to 20 of the judgment of the first Divisional Court [2000] All ER (D) 1675, in paragraphs 1 to 96 of the judgment of Ouseley J [2003] EWHC 2222 (QB), in paragraphs 3 to 9 of this court’s judgment [2004] EWCA (Civ) 997, and in paragraphs 13 to 74 of the judgment of the second Divisional Court [2006] EWHC 1038 (Admin) against which this appeal is brought. In spite of the submission by counsel for the Secretary of State of yet further historical material, much of it argumentative, it is unnecessary, in the light of the full narrative contained in the earlier judgments, to make reference to more of the factual history than is set out below. 

4.	Under an Immigration Ordinance made in 1971 by the Commissioner for BIOT, the inhabitants of the Chagos Islands were compulsorily removed, mainly to Mauritius, because Diego Garcia, the principal island in the archipelago, was required in the 1960s for use by the United States as a military base. The strategic significance of this base is a political judgment which there has been no attempt to question in these proceedings. Diego Garcia, however, is 100 miles from Peros Banhos and over 60 miles from the nearest of the other Chagos Islands. 

5.	Concomitantly with this process, in 1967 the Crown acquired the freehold interest in the entire territory of BIOT and in 1983 declared it Crown land. 

6.	In November 2000, a Divisional Court (Laws LJ and Gibbs J, [2001] QB 1067, DC) quashed the 1971 Ordinance on the ground that the exclusion of an entire population from its homeland lay outside the purposes of the parent Order in Council, the British Indian Ocean Territory Order 1965, which were limited to the governance of the population and did not encompass its expulsion. It is relevant to the present proceedings that it was the subsidiary Ordinance and not the empowering Order in Council which was quashed. 

7.	In October 2003 Ouseley J [2003] EWHC 2222 (QB) struck out civil proceedings for compensation and for a declaration of the claimants’ right to return to the Chagos Islands, holding that  none of the pleaded causes of action was sustainable. This court (The President, Sedley and Neuberger LJJ, [2004] EWCA (Civ) 997) upheld his decision in a judgment refusing permission to appeal. The judgment noted that the causes of action had been geared to the recovery of damages and that no separate claims to declaratory relief had been developed. It concluded: 

“It may not be too late to make return possible, but such an outcome is a function of economic resources and political will, not of adjudication.”

8.	The political will to repatriate the Chagossians to the Islands other than Diego Garcia had been evinced by the Foreign Secretary, Mr Robin Cook, in immediate response to the Divisional Court’s judgment of 3 November 2000: 

“I have decided to accept the Court’s ruling and the Government will not be appealing.

The work we are doing on the feasibility of resettling the Ilois [viz the Chagossians] now takes on a new importance. We started the feasibility work a year ago and are now well underway with phase two of the study.

Furthermore, we will put in place a new Immigration Ordinance which will allow the Ilois to return to the outer islands while observing our Treaty obligations.

The Government has not defended what was done or said thirty years ago. As Lord Justice Laws recognised, we made no attempt to conceal the gravity of what happened. I am pleased that he has commended the wholly admirable conduct in disclosing material to the Court and praised the openness of today’s Foreign Office.”

9.	The new Immigration Ordinance (Ordinance 4 of 2000) accordingly exempted from the need for an entry permit anyone who was a British Dependent Territories citizen by virtue of his or her connection with the BIOT. Such a connection existed if the applicant or one of his or her parents or grandparents had been born in the Chagos Islands, and the exemption covered the spouse and dependent children of any such applicant. In substance, the Chagossians were permitted to return home. 

10.	The feasibility study reported in 2002 that while short-term resettlement was feasible on a subsistence basis, long-term resettlement would be “precarious and costly”. There was no indication of any consequent change in government policy. 

11.	Then on 10 June 2004, a week before this court was to hear the application for permission to appeal from the decision of Ouseley J, two Orders in Council were placed by ministers before Her Majesty for approval: the British Indian Ocean Territory (Constitution) Order 2004 (“the Constitution Order”) and the British Indian Ocean Territory (Immigration) Order 2004 (“the Immigration Order”). In the Divisional Court’s words, the first of these Orders 

“declared that no person has the right of abode in BIOT nor the right without authorisation to enter and remain there. The Chagossians were thus effectively exiled.”

12.	It was not until 15 June 2004 that a written ministerial statement was placed before the House of Commons, citing the feasibility study (now two years old) and containing these paragraphs: 

“In effect, therefore, anything other than short-term resettlement on a purely subsistence basis would be highly precarious and would involve expensive underwriting by the UK government for an open-ended period - probably permanently. Accordingly, the Government considers that there would be no purpose in commissioning any further study into the feasibility of resettlement; and that it would be impossible for the Government to promote or even permit resettlement to take place. After long and careful consideration we have therefore decided to legislate to prevent it.

Equally, restoration of full immigration control over the entire territory is necessary to ensure and maintain the availability and effective use of the Territory for defence purposes, for which it was in fact constituted and set aside in accordance with the UK’s treaty obligations entered into almost 40 years ago. Especially in the light of recent developments in the international security climate since the November 2000 judgment, this is a factor to which due weight has had to be given.

It was for these reasons that on 10 June 2004 Her Majesty made two Orders in Council, the combined effect of which is to restore full immigration control over all the islands of the British Indian Ocean Territory. These controls extend to all persons, including members of the Chagossian community.”

13.	Thus, despite a candid ministerial acknowledgment to Parliament less than a month later that “the decisions made by successive governments in the 1960s and  1970s to depopulate the islands do not, to say the least, constitute the finest hour of UK foreign policy”, those decisions were replicated in 2004. 

The constitutional issues

14.	Although the Divisional Court dealt with it last, Mr Howell’s first ground of appeal is that any attack on the validity of a colonial Order in Council made under the royal prerogative is precluded by the Colonial Laws Validity Act 1865. His second and third grounds are, in substance, that the government of a ceded colony by Order in Council is not a ministerial act but a sovereign act of the Crown, challengeable only on the ground of incompatibility with imperial legislation. If either argument is right, the executive will have accomplished by Order in Council what it was prevented by the first Divisional Court decision from doing by Ordinance. 

(1) The Colonial Laws Validity Act 1865

15.	The 1865 Act is “An Act to remove Doubts as to the Validity of Colonial Laws”. I will come to the origin and nature of these doubts. By s.1 the Act includes in the term ‘colonial law’ laws made for any colony by Her Majesty in Council. It then provides (with the significant words emphasised): 

Colonial Law when void for Repugnancy

2. Any Colonial Law which is or shall be in any respect repugnant to the Provisions of any Act of Parliament extending to the Colony to which such Law may relate, or repugnant to any Order or Regulation made under Authority of such Act of Parliament, or having in the Colony the Force and Effect of such Act, shall be read subject such Act, Order, or Regulation, and shall, to the Extent of such Repugnancy, but not otherwise, be and remain absolutely void and inoperative.

Colonial Law when not void for repugnancy

3. No Colonial Law shall be or be deemed to have been void or inoperative on the Ground of Repugnancy to the Law of England,  unless the same shall be repugnant to the Provisions of some such Act of Parliament , Order, or Regulation as aforesaid.

16.	The Constitution Order and the Immigration Order are made by Her Majesty “by virtue and in exercise of all the powers in Her Majesty vested”. It is not contended that these powers include any created by statute; nor has it been suggested that any “third power” (see Elias v Secretary of State for Defence [2006] EWCA Civ 1203; cf Professor B.V.Harris (2007) 123 LQR 225) is in play. The recital that the Orders are made by Her Majesty “by and with the advice of her Privy Council” is purely formal: in reality the Privy Council plays no role beyond the placing by one of its members, a minister, of the instrument before the Monarch, who is called upon by constitutional convention to approve it. 
17.	The Constitution Order provides: 

No right of abode in the Territory

9. (1) Whereas the Territory was constituted and is set aside to be available for the defence purposes of the United Kingdom and the Government of the United States of America, no person has the right of abode in the Territory.

(2) Accordingly, no person is entitled to enter or be present in the Territory except as authorised by or under this Order or any other  law for the time being in force in the Territory.

18.	The Order goes on in s.15 to reserve to Her Majesty full power to make laws for the peace, good order and good government of the BIOT; to limit any challenges to those permitted by the 1865 Act; and to include in the lawmaking power the making of provision “for the purposes for which the Territory was constituted and is set aside”, including the punishment and removal of unauthorised entrants. The Immigration Order exempts military and government personnel from these controls; for others it provides for the grant of entry permits not exceeding four years in duration. Hence the Divisional Court’s brief and accurate summary of what has now been done. 
19.	The Secretary of State’s argument is simplicity itself: since there is no statute to which either Order is alleged to be repugnant, any challenge must be on the ground of repugnancy to the law of England, that is to say the common law. This being so, it is barred both by the phrase “but not otherwise” in s.2 and by the express terms of s.3. 
20.	The Divisional Court’s answer was equally succinct. Hooper LJ at §168 cited the Privy Council’s decision in Liyanage v The Queen [1967] AC 259, 284-5, for the proposition that the 1865 Act “abolished the vague doctrine of repugnancy” (a description adopted by the Privy Council from a commentary by Professor Keith) as a source of invalidity, so that 

“it was now necessary only for the colonial legislator to ascertain that there was no Imperial Act applicable and his field of action and choice of means became unfettered.”

The Divisional Court concluded (§169):

“In our judgment the 1865 Act does not preclude the public law irrationality challenge which we have upheld. We are not here concerned with repugnancy. As we have already said, ‘the act in question [was] the act of the executive’. As such it is amenable to judicial review.”

21.	Mr Howell submits that this will not do. Regardless of its source, he submits, an Order in Council is placed by the 1865 Act on a par with the Act of a colonial legislature and placed beyond challenge save for repugnancy to an imperial statute. In some cases Orders in Council are made pursuant to statutory powers, and there, Mr Howell accepts, repugnancy may operate. But where the power deployed is the prerogative power, he submits, there is no such constraint. 
22.	In my judgment the rule created by the 1865 Act is one of priority, not of powers: a colonial law, albeit validly enacted, is to be inoperative to the extent, but only to the extent, to which it conflicts with imperial statute law. That there exists a judicial power so to decide is assumed by the legislator: it is not a power created by the 1865 Act. Nor is the power of a colonial legislature unfettered: it will be limited by its own constitutive instrument and by the principle of territoriality, so that colonial judicatures remain able notwithstanding the 1865 Act to strike down local legislation which transgresses these limits. Likewise, those colonial Orders in Council made under statutory powers continued to be open to challenge not only for repugnancy to imperial legislation but, if they exceeded the powers which they purported to be exercising, for invalidity. 
23.	What then was Parliament’s intent in 1865 in relation to colonial enactments made in the exercise of the royal prerogative? The modern power of public law to review the use by ministers of the royal prerogative was unrecognised in the nineteenth century. The personal liability of ministers for breaches of private law in the exercise of their office under the Crown had been established by the courts during the eighteenth century (see Entick v Carrington (1765) 19 St.Tr. 1030), and the amenability of public authorities to the prerogative writs if they transgressed their powers was well established by 1865 (see Cooper v Wandsworth Board of Works (1863) 14 CB(NS) 180). But the reviewability of the acts of ministers in the exercise of the royal prerogative was not established until the landmark decision of the Divisional Court in R v Criminal Injuries Compensation Board, ex p Lain [1967] 2 QB 864.
24.	The kind of challenge mounted in this case cannot therefore have been in the mind of either the draftsman or the legislature when the 1865 Act was written and passed. There was, and still is, no question about the power of the Westminster parliament to legislate as it sees fit; but there was also in 1865 no question about the power of the Crown in Council to do likewise in relation to the colonies. Today there is not only a question about the latter: it is a question which has been conclusively answered by the CCSU case, to which I will come later in this judgment, in favour of the amenability of the royal prerogative, where the subject matter is appropriate, to judicial review. 
25.	In my judgment the 1865 Act had neither the purpose nor the effect of barring all such challenges. That Parliament in 1865 might have decided to exclude from the purview of the courts a form of challenge which was not believed to exist is not inconceivable; but when it concerns the access of the subject to Her Majesty’s courts such a suggestion falls to be cautiously scrutinised. The courts are reluctant to construe any but an unequivocal statutory provision as denying people access to them for the redress of justiciable wrongs, and for the reasons I have given, the Colonial Laws Validity Act 1865 is anything but unequivocal on the question. 
26.	This understanding of the Act sits with its known genesis. The “doubts” to which the Act was addressed had arisen from the activities of a single judge of the Supreme Court of South Australia, Boothby J, who had been making a habit of disapplying local legislation for non-conformity with what he took to be the principles of English common law or equity. To make its purpose doubly clear, the Act by s.7 explicitly deemed all South Australia’s laws to be valid “for all Purposes whatever”. The Law Officers’ Opinions on Imperial Constitutional Law (ed. O’Connell and Riordan, 1971), given between 1862 and 1864, which recommended and eventually produced the 1865 Act, devote close attention to the problems thrown up by Boothby J for the validity of South Australia’s own legislation but none to the use or validity of prerogative Orders in Council there or anywhere else. It is a fair inference that these were included by the parliamentary draftsman in the definition of colonial laws in s.1 for completeness, since they too were a source of colonial law, with the consequence that they acquired the same limited protection as local colonial statutes; but neither type of measure, in my judgment, is thereby immunised against a challenge, if the challenge is otherwise maintainable, to its validity as law. 
27.	This view is supported by Dicey’s account of the 1865 Act. In the eighth and last edition of his Introduction to the Study of the Law of the Constitution (1915), pp.49-50, he wrote: 

“The charter of colonial independence is the Colonial Laws Validity Act, 1865.

This statute seems (oddly enough) to have passed through Parliament without discussion; but it permanently defines and extends the authority of colonial legislatures ….

The importance, it is true, of the [Act] may well be either exaggerated or quite possibly underrated. The statute is in one sense less important than it at first sight appears, because the principles laid down therein were, before its passing, more or less assumed, though with some hesitation, to be good law and to govern the validity of colonial legislation. From another point of view, the Act is of the highest importance, because it determines, and gives legislative authority to, principles which had never before been accurately defined, and were liable to be treated as open to doubt.  In any case the terms of the enactment make it now possible to state with precision the limits which bound the legislative authority of a colonial parliament.”

It is apparent both from Dicey’s repeated references to colonial legislatures or parliaments and from his omission of s.1 from his citation of the “main provisions” of the Act that little if any significance was attached to the inclusion of Orders in Council in the category of colonial laws for the purposes of the Act. The entire focus was on the empowerment of colonial legislatures to do as they thought best, so long what they did was not repugnant to any imperial enactment.
28.	In Liyanage v The Queen [1967] AC 259 the Privy Council declined to interfere on grounds of vires (though they did interfere on grounds of constitutionality) with retrospective penal legislation passed by the Sri Lankan parliament. They had been pressed in argument with Lord Mansfield’s holding in Campbell v Hall (1774) 1 Cowp. 204, 209, that the King’s authority to make new laws for colonies was “subordinate to his own authority in Parliament”, so that “he cannot make any new change contrary to fundamental principles”; but their Lordships held that this “vague and uncertain phrase” could not stand with the Colonial Laws Validity Act 1865. It may fairly be said that, however vague the notion  of fundamental principles had come to seem by the mid-20th century, they will have had a fairly solid meaning for Lord Mansfield and his contemporaries, starting with the inviolability, save by due process of law, of property and person. No reasoning, however, was addressed to the present question (which had been canvassed in argument) whether there may be conditions of validity which precede any question of repugnancy; and this although their Lordships went on to hold that the legislation was unconstitutional. 
29.	While, as Laws LJ said in Bancoult (No 1), §42, it is right that we should treat decisions of the Privy Council in matters of colonial law as uniquely authoritative (though I would also adopt the caveat entered by Waller LJ at § [86]    below about the different world in which such received law now falls to be applied), the decision in Liyanage does not appear to me to address the present question. More to the point, in Macleod v A-G for New South Wales [1891] AC 455 the Privy Council, without any perceived restraint arising from the 1865 Act, read down a colonial statute which purported to penalise persons who had committed bigamy anywhere in the world, on the ground that on any wider reading “it would have been beyond the jurisdiction of the Colony to enact such a law”.
30.	Repugnancy as a legislative term means an irreconcilable conflict between two laws. There is no reason to import into the scheme of the 1865 Act any departure from the logical principle that before any question of repugnancy to an Act of the imperial Parliament can arise, a colonial measure has first to be law. If an unconstitutional colonial statute is not law – as manifestly it is not - no question of repugnancy arises. The present dispute, equally, is not about whether the Constitution Order is repugnant to a superior statute or other legal provision but about whether it is law. It is accordingly not barred by the 1865 Act.

(2)  Sovereign power

Monarch or minister

31.	The Privy Council in Sammut v Strickland [1938] AC 678, 697, in deciding the validity of prerogative letters patent granting representative government to Malta, took the extent of the royal prerogative to be “a pure question of English common law”, and their task as being to determine its extent. Mr Howell accepts that since the Case of Proclamations (1611) 12 Co.Rep.74 the common law has held it beyond the Crown’s power to legislate domestically without the advice and consent of Parliament. But he contends that the powers which are exercised by Her Majesty in Council when legislating for a colony are “the same as those which she may exercise in Parliament” - in other words, that they are plenary sovereign powers. The only qualifications he is prepared to accept are that the power must not be exercised repugnantly to any imperial parliamentary legislation or inconsistently with the principle of territoriality. The question now to be decided is whether there are today at common law any larger constraints upon the prerogative power to legislate for the colonies.
32.	The argument that there are none is one which, to borrow Lord Atkin’s words in Liversidge v Anderson [1942] AC 206, 244, might have been addressed acceptably to the Court of King’s Bench in the time of Charles I; though it might have been less acceptable in the time of James I, when Coke CJ was in office. Particularly in the light of Mr Howell’s assertion that “1688 did not change this”, a full critique of it would call up the entire constitutional history of this country over the last four centuries. But the point was put simply, if schematically, by Anson in his Law and Custom of the Constitution (3rd ed, 1907), II.i, p.41:

“The position of affairs has been reversed since 1714 [viz the accession of George I]. Then the King or Queen governed through Ministers, now Ministers govern through the instrumentality of the Crown.”

Or as Lord Diplock put it in Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374, 409:

“…. in the absence of any statute regulating the subject-matter of the decision the source of the decision-making power may still be the common law itself, i.e. that part of the common law that is given by lawyers the label of ‘the prerogative’. Where this is the source of the decision-making power, the power … in constitutional practice is generally exercised by those holding ministerial rank.”

If this is right, and modern authority repeatedly holds that it is, any amenability to judicial review in relation to the use of the royal prerogative is that of ministers, not of the Monarch in whose name they govern. Hence, for instance, the title of these proceedings. Hence, too, the ministerial account to Parliament of the measures which have brought them about:

“Due to the fact that settlement is not feasible, the Government decided … to legislate to prevent it.”

33.	Mr Howell nevertheless submits that constitutionally and legally it is the Monarch and not the minister who makes a colonial Order in Council, and – what does not necessarily follow - that this places the process outside the jurisdiction of the courts. He cites in support a passage from Quark Fishing [2005]  UKHL 57, §12, in which Lord Bingham says of the Secretary of State’s instruction to the Commissioner for South Georgia and the South Sandwich Islands (SGSSI): 

“Such power and authority can be exercised only by the Queen, who in this context is (and is only) the Queen of SGSSI. It is in my view correct in constitutional theory to regard the Secretary of State as her mouthpiece and medium.”

Read in its context, this passage seems to me to support, if anything, the contrary view. The context was not the making of a legislative instrument in the name of the Crown; it was the issuing by a minister of an instruction pursuant to an Order in Council which authorised Her Majesty to issue such instructions through a Secretary of State but gave ministers no independent powers. In constitutional theory, as Lord Bingham says, it followed that it was the Queen who was the author of the instruction. In constitutional reality it was, of course, the Secretary of State. The reason why the theoretical position mattered was that the appeal turned on whether the Queen, in – albeit theoretically - issuing the instruction through her minister, was acting in right of SGSSI rather than of the United Kingdom.  What neither Quark Fishing nor any other case decides is that the theoretical source of a measure in the Crown protects it from legal challenge as an executive act, which is what it substantively and constitutionally is. Were it otherwise, no judicial review of central government action could ever take place.
34.	The government’s stance before us can be tested by considering whether, had the Secretary of State made his announcement the week before rather than the week after the making of the two Orders in Council, a prohibiting order could have been sought, on the same grounds as are now before us, to prevent him from laying the draft Orders before Her Majesty for her approval. Mr Howell’s first answer was that this would be as impermissible as trying to restrain a minister from laying a Bill before Parliament. But this is plainly not so, since the Crown in its prerogative function enjoys no protection akin to article 9 of the Bill of Rights. His next answer was that any such preventive step would infringe the Crown’s sovereign power. But this is to clothe ministers with an immunity from the supervisory jurisdiction of the courts which the decision of the House of Lords in M v Home Office [1994] 1 AC 377 explicitly denies them. It would be no better if the answer were that the minister is, but the Monarch is not, amenable to the court’s jurisdiction, for there would then be a distinction which depended solely on the point of time at which the challenge was made and not on any overarching constitutional sovereignty. 

35.	The only acceptable answer, in my judgment, is that an Order in Council is an act of the executive and as such is amenable to any appropriate form of judicial review, whether anticipatory or retrospective. What determines the constitutional status of a measure – a statute, a judgment or an order - is not its formal authority, which is always that of the Crown, but its source in the interlocking but unequal limbs of the state. One aspect of this structure, determined by the historic compromise reached in the course of the 17th century, is that both the courts and the executive will treat the authority of Parliament, duly exercised, as absolute. Another aspect, upon which both democratic governance and the rule of law depend, is that the courts will respect all acts of the executive within its lawful province, and that the executive will respect all decisions of the courts as to what its lawful province is (M v Home Office [1992] QB 270, 314, per Nolan LJ, cited in Bradley and Ewing, Constitutional and Administrative Law, 14th ed, 2007, p.90).  
36.	This case, correspondingly, concerns not a sovereign act of the Crown but a potentially justiciable act of executive government. Were we to hold otherwise we would be creating an area of ministerial action free both of Parliamentary control and of judicial oversight, defined moreover not by subject-matter but simply by the mode of enactment. The implications of such a situation for both democracy and the rule of law do not need to be spelt out.

Limitations of principle

37.	In this situation Mr Howell falls back upon the submission that colonial governance is a function of the prerogative set by its subject-matter beyond legal challenge. Before turning, however, to restrictions derived from subject-matter, it is relevant to see what constraints exist in principle upon the use of the prerogative power for colonial governance, because they are in my judgment more extensive than Mr Howell’s argument from sovereignty allows. To begin with, the rule against repugnancy is not an artefact of the Colonial Laws Validity Act 1865: it was a pre-existing rule of common law which was reduced by the 1865 Act to a single rule of priority. The underlying principle is that the common law limits the use of the colonial prerogative power to its proper purposes. It has thus been manifest since the early 17th century that any Order in Council which, while purporting to legislate for the colonies, legislated for Britain would be void and liable to be so declared by the courts. Until the passing of the British Settlements Act 1887, the same will have been true of any Order in Council which purported to legislate for a settled colony. The same, if Lord Mansfield was right in Campbell v Hall, is true of any act of governance incompatible with the terms upon which the colony in question has been ceded or surrendered. 
38.	Next, there can be no doubt that the courts will not allow the power to be used corruptly: if, for example, it were to be proved that a minister or one of his or her advisers had been bribed to include a particular provision in a colonial Order in Council, the Order would be wholly or in part struck down. An Order in Council permitting the use of torture to obtain evidence would today fall under the 1865 Act as being repugnant to an imperial statute (the Criminal Justice Act 1988, s.134), but even before 1988 the courts of this country would surely have struck it down, whether on the public law ground articulated by Lord Diplock in CCSU that it was irrational in its defiance of accepted moral standards, or on Lord Mansfield’s ground in Campbell v Hall that it was “contrary to fundamental principles”. The same would almost certainly be the case with an Order in Council abolishing all recourse to law in a colony or introducing forced labour. And while the extent of the United Kingdom’s territory may itself be irrebuttably determined by the executive (see Post Office v Estuary Radio [1968] 2 QB 740), prerogative legislation which purported to operate outside the limits so determined would – as I think Mr Howell accepts – be open to judicial review. These instances of legitimate judicial intervention to prevent the abuse of prerogative power by executive government go considerably wider than the government’s argument before us has allowed. 
39.	At first sight, the foregoing sits uneasily with what was said by this court in Nyali Ltd v A-G [1956] 1 QB 1:

“Once jurisdiction is exercised by the Crown the courts will not permit it to be challenged. Thus, if an Order in Council is made affecting the protectorate, the courts will accept its validity without question…” (per Denning LJ).

The argument, however, had been based upon a commercial agreement between the plaintiff company and the government of Kenya, with which the Order in Council was said to be in conflict. This is reflected in the way Parker LJ put his assenting judgment:

“… these courts will not consider the limits of the jurisdiction granted by treaty or otherwise to her Majesty. Such limits may be extended by sufferance and usage and the courts will and must assume that the legislative or other acts in question are within the jurisdiction granted. All that they can do is look at the instrument manifesting the exercise of the jurisdiction to see whether it has been lawfully exercised, according to the law in force.”

In my view Nyali does not have the breadth of application which Mr Howell attributes to it. The case was about the meaning of “military” in an exemption contained in the agreement for bridge tolls, and it was the Crown which relied on the prerogative, specifically the prerogative right not to pay bridge tolls, as an aid to the construction of the agreement. The Order in Council was material only to the extent that it introduced the Crown’s prerogatives into the governance of the Kenya protectorate. As can be seen from the way Parker LJ expressed himself, whether such measures are ever challengeable was not in issue. The decision is in my view authority, at most, for the proposition that the meaning of an Order in Council cannot be determined or modified by exogenous factors. 

40.	The modern locus classicus is in the speech of Lord Scarman in Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374, 407:
“My Lords, I would wish to add a few, very few, words on
the reviewability of the exercise of the royal prerogative. Like
my noble and learned friend Lord Diplock, I believe that the law
relating to judicial review has now reached the stage where it can
be said with confidence that, if the subject matter in respect of
which prerogative power is exercised is justiciable, that is to say
if it is a matter upon which the court can adjudicate, the exercise
of the power is subject to review in accordance with the principles
developed in respect of the review of the exercise of statutory
power. Without usurping the role of legal historian, for which I
claim no special qualification, I would observe that the royal
prerogative has always been regarded as part of the common law,
and that Sir Edward Coke had no doubt that it was subject to
the common law: Case of Prohibitions del Roy (1607), 12 Co. Rep.
63 and Case of Proclamations (1611) 12 Co. Rep. 74. In the
latter case he declared, at p.76, that "the King hath no
prerogative, but that which the law of the land allows him." It is,
of course, beyond doubt that in Coke's time and thereafter judicial
review of the exercise of prerogative power was limited to
inquiring into whether a particular power existed and, if it did,
into its extent: Attorney-General v. De Keyser's Royal Hotel Ltd.
[1920] A.C. 508. But this limitation has now gone, overwhelmed
by the developing modern law of judicial review: Reg. v. Criminal
Injuries Compensation Board, Ex parte Lain [1967] 2 Q.B.864 (a
landmark case comparable in its generation with the Case of
Proclamations) and Reg. Secretary of State for Home Affairs,
Ex parte Hosenball [1977] 1 W.L.R. 766. Just as ancient
restrictions in the law relating to the prerogative writs and orders
have not prevented the courts from extending the requirement of
natural justice, namely the duty to act fairly, so that it is
required of a purely administrative act, so also has the modern
law, a vivid sketch of which my noble and learned friend Lord
Diplock has included in his speech, extended the range of judicial
review in respect of the exercise of prerogative power. Today,
therefore, the controlling factor in determining whether the
exercise of prerogative power is subject to judicial review is not
its source but its subject matter.”

41.	Among recent authorities which assert or recognise the amenability in principle of prerogative power to judicial review, it is sufficient to cite what this court concluded in R (Abbasi) v Secretary of State for Foreign and Commonwealth Affairs [2002] EWCA 1598, §106:

“It is not an answer to a claim for judicial review to say that the source of the power of the Foreign Office is the prerogative. It is the subject-matter that is determinative.”

42.	Mr Howell submits that the legitimate and therefore unreviewable extent of the royal prerogative should be gauged by the breadth of powers which can be delegated or conveyed by it: if the prerogative can be used, as it has regularly been, to convey full constitutional sovereignty to a colony, the Crown necessarily possesses powers at least as large as those it conveys. In other words, the power of colonial governance, being sovereign, is beyond the reach of the courts. This syllogism, insofar as it does not assume the very thing it seeks to prove, proceeds on the basis that local sovereignty is granted or conveyed by the metropolitan power rather than simply brought about by the relinquishment of imperial sovereignty. The grant of independence represents an undoubted exercise of the historic prerogative of the Crown to govern or cede dominions and colonies which it has in the past acquired, but it is analytically an act which, by releasing a colony from external rule, enables the colony to exercise sovereignty in its own right: an act not of gestation but of parturition. The transitional problem, considered in Buck v A-G [1965] 1 Ch 745, of how a constitution composed by the parent state becomes part of the newborn state does not affect this. Nor do cases such as  Ex parte Sekgome [1910] 2 KB 576 which concern protectorates – foreign countries whose governance, as explained in Sabally and N’Jie (above), is an act of state.
43.	Mr Howell’s reasoning therefore tells us nothing definite in a case such as the present, which concerns an unprecedented use, or purported use, of the power of colonial governance. It will be necessary to consider in due course how wide the power to provide for the peace, order and good government of a colony is, and whether the courts can go behind the executive’s assertion that it is the end to which a measure is directed. But in my judgment there is no legal basis for any prior restriction on the grounds upon which executive acts carried out by Order in Council may be judicially reviewed. Provided the subject-matter is apt for adjudication, any abuse of power in the making or the operation of such an instrument is in principle justiciable. So I come back to the question whether colonial governance is one of the prohibited categories of subject-matter.

Limitations of subject-matter

44.	In the CCSU case (ante) it was accepted, as Sir Sydney in turn accepts, that there are executive acts which by their nature are either not justiciable in public law or at most are justiciable on narrow grounds.  Lord Roskill (at 418)  said this of them:

“…I do not think that that right of challenge can be unqualified. It must, I think, depend upon the subject-matter of the prerogative power which is exercised. Many examples were given during the argument of prerogative powers which as at present advised I do not think could properly be made the subject of judicial review. Prerogative powers such as those relating to the making of treaties, the defence of the realm, the prerogative of mercy, the grant of honours, the dissolution of Parliament and the appointment of ministers as well as others are not, I think, susceptible to judicial review because their nature and subject matter are such as not to be amenable to the judicial process. The courts are not the place wherein to determine whether a treaty should be concluded or the armed forces disposed in a particular manner or Parliament dissolved on one date rather than another.”

45.	Mr Howell submits that the omission of colonial governance from the list of unreviewable uses of the royal prerogative is an oversight. That seems unlikely. But it would be a mistake to jump to the opposite conclusion that their Lordships considered the colonial governance power to be within the reach of judicial review. It is likelier that it was left for decision when it arose, which is now.
46.	It can be observed without disrespect, particularly since Lord Roskill was careful to express himself tentatively, that a number of his examples could today be regarded as questionable: the grant of honours for reward, the waging of a war of manifest aggression or a refusal to dissolve Parliament at all might well call in question an immunity based purely on subject-matter. By the same token, one can readily accept that the colonial use of the prerogative power is for the most part beyond the reach of judicial review, but not that it is always or necessarily so. As we shall see, considerable latitude is given to the executive in deciding what makes for the peace, order and good government of a colony; but, as Laws LJ said in Bancoult (No.1) [2001] QB 1067, §55, large though the tapestry is, every tapestry has a border. The respondent accepts that anything sensibly capable of providing for the peace, order and good government of a colony will, by virtue of its subject-matter, lie within that border. But the border itself is a double one. In the first place, even if its subject-matter is incontestably the peace, order and good government of the colony, it is capable of being rendered invalid by jurisdictional error or malpractice of the kinds I have instanced earlier. In the second place, it must also be open to challenge if its subject-matter, on examination, is manifestly not the peace, order and good government of the colony.
47.	For these reasons I would hold that the use of the prerogative power of colonial governance enjoys no generic immunity from judicial review. What are immune, in my judgment, are prerogative measures lawfully enacted and rationally capable of addressing the peace, order and good government of the colony.

The public law issues

48.	The next question is therefore whether s.9 of the Constitution Order, and with it the Immigration Order, is lawfully made. The challenges to it are these: first, that it is ultra vires because it is unconnected with the governance of the BIOT; secondly, and alternatively, that it falls to be quashed for irrationality (the ground on which the Divisional Court quashed it) or for breach of the Chagossians’ legitimate expectation of a right of return; thirdly, that it is in principle reviewable for breach of the European Convention on Human Rights, the Human Rights Act 1998 and principles of public international law.
49.	I describe the third group of issues as issues in principle only because, in a pragmatic endeavour to keep the litigation within bounds, Sullivan J directed that these issues were not to be determined on the judicial review hearing but were to be reserved for further hearing “if relevant”. The only live question about them, at least for the moment, is therefore whether they are relevant, which I take to mean arguable: but in the light of my conclusions under the first and second heads I do not think it necessary, or perhaps wise, to embark upon the complex questions they throw up.

The objects of colonial governance

50.	The phrase “peace, order and good government”, which has a long legislative pedigree, has become a term of art in the sense that it is regularly used without further explanation to denote the delegation of large but undefined powers to a nominated rule-maker. Since at its fullest it can bring about the creation of independent states, it is a power of the greatest importance carrying commensurate responsibilities. Mr Howell, while relying on its breadth where it is used by the Crown to delegate powers, does not accept that it constrains the prerogative power itself. For reasons to which I now come, I would hold that, however expressed, the original prerogative power of colonial governance and the commonly delegated power to provide for peace, order and good government have  similar breadth and similar boundaries. Indeed, the distinction made by Mr Howell between the two things is reduced to vanishing point by the very amplitude he derives from the prerogative and attributes to the formula.
51.	Although, as will be seen, the formula has historically been regarded in the jurisprudence of the Privy Council as an expansive concept, it is necessary also to have in mind that it has limits, even if these are self-imposed. To see the formula, as I would, as directed to the wellbeing of a dependent territory and its population is both to accord a very wide discretion to the imperial state in deciding what is best for a colony and to affirm that, like every discretion, it is limited by and to its own expressed objects. It is not the function of the courts to criticise the executive’s judgment of these, much less to substitute their own view of what is best for a colony. But, for reasons I have given, it is their constitutional function to decide whether what has been enacted (or what it is proposed to enact) is rationally and legally capable of providing for a colony’s wellbeing. If it is not, then it falls outside the prerogative power.
52.	Mr Howell has chosen to rely on two expulsion cases, the Japanese Canadians case [1947] AC 87 and Zabrowsky v GOC Palestine [1947] AC 246 to support his argument that the Crown’s unchallengeable powers can extend to arbitrary and, on the face of them, unjust removals. These were decisions from the same period as Liversidge v Anderson and they ought in my view to be regarded as the majority decision in Liversidge v Anderson is now regarded – as “expediently and, at that time, perhaps excusably wrong” (R v IRC ex parte Rossminster Ltd [1980] AC 952, per Lord Diplock).
53.	Of the large number of cases we have been asked to consider on the ambit of “peace, order and good government”, the one I have found most illuminating is the decision of the New South Wales Court of Appeal in Building Construction Federation v Minister for Industrial Relations (1986) 7 NSWLR 372. Giving the leading judgment, Street CJ, albeit upholding the validity of a law which directed a particular outcome of a judicial act, held that the words of the formula “prescribe and confine the scope of the legislative field open to the New South Wales Parliament”. He went on:

“It appears to be generally assumed that these words confer unlimited legislative power, comparable with that vested in the English Parliament itself. I can find no satisfactory basis for that assumption. The words, by their very terms, confine the powers conferred to ‘peace, welfare and good government’ of the body politic in respect of which the legislature is being established.

Assertions that these words convey plenary, or sovereign, power are to be found frequently in cases in which it has been felt necessary to reject any suggestion that the legislature in question is a mere delegate of the English Parliament and thus is not able to delegate further the law-making powers vested in it. Such suggestions have been uniformly rejected. But the rejection of such suggestions on the basis that the words convey plenary or sovereign power does not necessarily import that the power is unlimited in scope.”

Street CJ went on to cite a passage from the judgment of the Privy Council in R v Burah (1873) 3 App Cas 889 which acknowledged that it was only when acting within the limits of the mandate set by Act of the imperial Parliament that the Indian legislature possessed plenary powers. It is right to say that Kirby P, whose scholarly judgment follows that of Street CJ, was minded to equate the devolved power with Parliamentary sovereignty. Priestley J took a view more consonant with that of Street CJ. It seems to me that the considerations which affect a devolved legislature, and which determined the Building Federation case in favour of judicial non-intervention, are markedly more powerful, for reasons considered earlier in this judgment, than those which affect the ministerial deployment of prerogative powers.
54.	In Bancoult (No 1) [2001] QB 1067 the Divisional Court held that the power given to the Commissioner by s.11 of the 1965 BIOT Order in Council to make laws for the peace, order and good government of the territory did not empower him to make an Ordinance exiling its entire population. In a passage (§57) which deserves citation in full, Laws LJ said this:

S.4 of the Ordinance effectively exiles the Ilois from the territory where they are belongers and forbids their return. But the “peace, order, and good government” of any territory means nothing, surely, save by reference to the territory’s population. They are to be governed: not removed. In the course of argument Gibbs J gave what with respect seems to me to be an illuminating example of the rare and exceptional kind of case in which an order removing a people from their lawful homeland might indeed make for the territory’s peace, order and good government: it would arise where because of some natural or man-made catastrophe the land had become toxic and uninhabitable. Short of an extraordinary instance of that kind, I cannot see how the wholesale removal of a people from the land where they belong can be said to conduce to the territory’s peace, order and good government. The people may be taxed; they should be housed; laws will criminalise some of the things they do; maybe they will be tried with no juries, and subject to severe, even brutal penalties; the laws made for their marriages, their property, and much besides may be far different from what obtains in England. All this is vouchsafed by the authorities. But that is not all the learning gives. These people are subjects of the Crown, in right of their British nationality as belongers in the Chagos Archipelago. As Chitty said in 1820, the Queen has an interest in all her subjects, who rightly look to the Crown - today, to the rule of law which is given in the Queen’s name - for the security of their homeland within the Queen’s dominions. But in this case they have been excluded from it. It has been done for high political reasons: good reasons, certainly, dictated by pressing considerations of military security. But they are not reasons which may reasonably be said to touch the peace, order and good government of BIOT, and in my judgment this is so whether the test is to be found in our domestic public law, exemplified by the Wednesbury doctrine or in a more, or less, intrusive approach. In short, there is no principled basis upon which s.4 of the Ordinance can be justified as having been empowered by s.11 of the BIOT Order. And it has no other conceivable source of lawful authority.

55.	Once it is accepted that a colonial Order in Council is susceptible of judicial review on the grounds I have indicated, it is Sir Sydney Kentridge’s submission that this passage concludes the argument in his favour. What it establishes in relation to the commissioner’s Ordinance must be equally true, he argues, of the government’s Order in Council: that by exiling the population it has sought to do something which not only does not relate to the peace, the order or the good government of the Chagos Islands but which is antithetical to these ends. The argument stands on two distinct bases: first, that it has been conclusively decided as between the present parties; alternatively, that it is right.
56.	The first argument takes as its starting point the proposition that there is no universal bar to the application of the res judicata doctrine to public law questions. In most cases, no doubt, there will be no identity of parties, but where the parties are the same, the issue is the same and the judgment unappealed, the rule against relitigation arguably operates. So here, it is submitted, government cannot seek to reopen the proposition that exiling the entire Chagossian population is in law beyond the power to provide for the peace, order and good government of the BIOT. Accepting this for the present, the arguably significant disparity between the two cases is that, while peace, order and good government were spelt out in the 1965 Order as objects of the commissioner’s powers, they are relied on before us not as prescribed limits having the force of law but as shorthand for a common law power without effective, or at least justiciable, limits. It seems to me preferable in the circumstances to deal with the issue on its merits.

Abuse of power

57.	The Divisional Court which heard the present claim concluded that, on its merits, the enactment of s.9 of the Constitution Order was irrational. This was because, as Mr Howell accepts before us, it was in right of the BIOT and not of the United Kingdom that Her Majesty made the two Orders. It followed, in the Divisional Court’s judgment, that the United Kingdom’s own interests, a fortiori those of the United States, could play no legitimate part in determining what was appropriate to the good government of the BIOT. The Divisional Court declined to entertain the difficulties of resettlement, to which the Orders made no reference at all, as a further justification of them, but pointed out that if this contention were to be entertained it would encounter a powerful argument from legitimate expectation. Before us all these issues are alive.
58.	Before I turn to them, however, it is right to note two topics on which Mr Howell put the Secretary of State’s case with calculated restraint. The first was the issue of the United Kingdom’s strategic interests: while submitting that these were relevant and admissible reasons for making the Orders, Mr Howell did not seek to equate them with the national security interests which furnished a complete answer in the CCSU case. The second was the importance of the right of return. While maintaining his stand on the relevance of the practical difficulties of providing a returning population with the infrastructure required for survival, Mr Howell was careful not to dismiss the idea of return as mere nostalgia. I think this both commendable and right. Few things are more important to a social group than its sense of belonging, not only to each other but to a place. What has sustained peoples in exile, from Babylon onwards, has been the possibility of one day returning home. The barring of that door, however remote or inaccessible it may be for the present, is an act requiring overwhelming justification.
59.	There are in my judgment difficulties both with Sir Sydney’s principal assault on the Orders as ultra vires and with the Divisional Court’s classification of them as irrational. But they are difficulties of taxonomy, not of substance. The concept of ultra vires acts was borrowed during the 19th century by public law from company law, where powers are spelt out in articles of association and acts can be measured against them. The same is frequently the case in public law: hence the transferability of the concept. But here we have no empowering statute or measure; only the indefinite royal prerogative. Similarly, the Divisional Court’s explanation (§122) of why the Orders are irrational reveals no true flaw of logic but rather an inadmissible or collateral purpose:

It follows, in our judgment, that section 9 of the Order is irrational on public law grounds and (subject to the other arguments) must be quashed for this reason. Made by the Queen in right of BIOT, the Order is, on its face, not concerned with the interests of BIOT, but with the interests of the United Kingdom and of the United States. We make it clear that we are not making any judgment about the defence interests of the United Kingdom or the United States- all that we are saying is that the validity of the Order in Council made by the Queen in right of BIOT has to be tested by reference to the interests of BIOT. This Order in Council conspicuously does not do that.

60.	What is being addressed by all these arguments, and by the argument on legitimate expectation too, is the abuse of power. This is what the courts of public law are there to identify and, in proper cases, to correct: see the powerful body of citations assembled in Fordham Judicial Review Handbook, 4th ed, §45.2.5. Power may be abused in a variety of ways, of which acting beyond the limits of the power is one, acting irrationally is another, acting for an improper purpose is a third and acting so as to frustrate a legitimate expectation is a fourth; and there are more, both procedural and substantive. Very commonly they run into one another, as Lord Greene MR pointed out in the Wednesbury case [1948] 1 KB 223. Particularly when one is considering an allegation of abuse of the prerogative power, the search for categories of abuse may therefore be less important than the search for principle; for, as Wade and Forsyth comment, the “remarkable” decisions of the courts in the later 20th century that judicial review runs to prerogative and self-constituted bodies

“were prompted by the courts’ determination to act ‘in defence of the citizenry’ [per Sir John Donaldson MR in Datafin [1987] QB 815, 839] against abuse of power by important bodies of a governmental or quasi-governmental nature … and not to let them escape merely because of their non-statutory character” (Administrative Law, 9th ed, p.346).

61.	This is why (see Craig, Administrative Law, 5th ed, p.18) it is possible but analytically unhelpful to include in the concept of vires powers conferred or limitations imposed by the common law. But a rights-based approach is not the only or perhaps even the true alternative. What modern public law focuses upon are wrongs – that is to say, unlawful acts of public administration. These often, of course, infringe correlative rights, but they do not necessarily do so: hence the test of standing for public law claimants, which is interest-based rather than rights-based. Correspondingly, what the court is in essence invited to do in the present case is to hold that the making of s.9 of the Constitution Order, and of the entire Immigration Order, was an abuse of the prerogative power of the Crown because the Crown’s common law powers do not extend to the exiling of an entire population. If this is right, categorising it as an ultra vires act or as an irrational one or as a breach of a legitimate expectation is an important matter of legal taxonomy but not critical to the finding of legal fault.
62.	Mr Howell is no doubt right (see Abbasi ante) to assert that the Crown’s duty of protection towards its subjects is not legally enforceable; but, as Sir Sydney submits, it does not follow that the courts cannot intervene to prevent a breach of it. Mr Howell’s response to this is that in point of fact government had due regard to the interests of all those to whom the Crown owed a duty of protection: as he puts it in his skeleton argument, regard was had not only to the interests of the Chagossians but to the interests of the (British) taxpayers who would have to fund their resettlement and to the defence and security interests of the United Kingdom and its allies. These are exactly the considerations which Sir Sydney contends the Crown in right of the BIOT had no power to address. Mr Howell, recognising that his task would be markedly easier if he were able to say that the Orders were made in right of the United Kingdom, contends nevertheless that the interests to which government may have regard, albeit in right of the BIOT, are both catholic and indivisible. He has been able to deploy potent authority in support of the proposition that, even accepting that the courts have a power to intervene where the prerogative power is exceeded or abused, the legitimate extent of the prerogative in right of the colonies is so broad that nothing that has happened in the present case is capable of having transgressed it.
63.	Thus in Ibralebbe v The Queen [1964] AC 900, 923, the Privy Council held:

“The words ‘peace, order and good government’ connote, in British constitutional language, the widest law-making powers appropriate to a Sovereign.”

In Riel v The Queen (1885) 10 App. Cas. 675, 678, their Lordships, per Lord Halsbury LC, described the same words in the British North America Act 1871 as “apt to authorise the utmost discretion of enactment for the attainment of the objects pointed to”:

“They are words under which the widest departure from criminal procedure as it is known and practised in this country have been authorised in Her Majesty’s Indian empire. Forms of procedure unknown to the English common law have there been established and acted upon, and to throw the least doubt upon the validity of powers conveyed by those words would be of widely mischievous consequence.”

Where there are no such governing words, therefore, the prerogative power to legislate for the colonies must, Mr Howell submits, be a truly sovereign power: in the words of the Privy Council in Liyanage (ante, 286), “the full legislative powers of a sovereign independent state”.
64.	Sir Sydney, however, points to the words which follow:

“Those powers, however, as in the case of all countries with written constitutions, must be exercised in accordance with the terms of the constitution from which the power derives.”

Exactly the same, he submits, is true of a country such as the United Kingdom whose constitution, though unwritten, is no less real. For reasons given earlier in this judgment I would accept this submission: the royal prerogative, while the common law accords it a very large area of judgment and discretion in colonial matters, is not unlimited or unreviewable. It may still be, as the decided cases from an earlier phase of Britain’s imperial history hold, that it is not a sufficient objection that what has been enacted colonially would be improper or unconstitutional if done here. But it may also be that Lord Mansfield was right before his time when he held in Campbell v Hall (1774) 1 Cowp. 204, 209, that the colonial prerogative power was such that the Monarch “cannot make any new change contrary to fundamental principles”.
65.	Unless the administration of the United Kingdom’s remaining colonies is to be an Alsatia where the rule of law does not run, in my judgment the latter must today be the case. One need look no further than the documentation disclosed in the first Bancoult case [2001] QB 1067 to see how keenly aware the Colonial Office was both of the importance of the principle that a state could not displace subject populations at will, and of the need to circumvent it. 
66.	Mr Howell submits that since the governance of a territory can affect many other things than its population, especially where it has none, there can be no principle which requires a sole or even primary regard to be had to the population where there is one. This seems to me a non sequitur: the presence of a human population must make a fundamental difference to the proper concerns and actions of government. And while many elements, for example commercial and ecological, may properly affect how the population is governed, this case concerns not its governance but its elimination as a population. 
67.	The governance of each colonial territory is in constitutional principle a discrete function of the Crown. That territory’s interests will not necessarily be the interests of the United Kingdom or of its allies. This is not to say that the two things are mutually exclusive: they will often, perhaps usually, be interdependent, so that the defence of a colony from attack, and even its use as a base to protect the United Kingdom, may serve both its and the United Kingdom’s interests. But that is not the case here. I respectfully agree with the view of both Divisional Courts that, while a natural or man-made disaster could warrant the temporary, perhaps even indefinite, removal of a population for its own safety and so rank as an act of governance, the permanent exclusion of an entire population from its homeland for reasons unconnected with their collective wellbeing cannot have that character and accordingly cannot be lawfully accomplished by use of the prerogative power of governance.

Good reason?

68.	I turn, then, to the reasons which are advanced, remembering what Lord Hoffmann said in Quark Fishing (ante) at §78: that an examination of the location and balance of the varying interests which a measure was designed to meet “would be something for which a court is not at all well suited”, although he declined to hold that it was not justiciable. In my view, for the reasons which follow, we are not called upon to make any evaluation of this kind.

69.	The single ground given in s.9(1) of the Order itself for exiling the population is strategic:

“Whereas the Territory was constituted and is set aside to be available for the defence purposes of the Government of the United Kingdom and the Government of the United States of America, no person has the right of abode in the territory.”

The desire of the United States administration, reiterated in statements made for the purpose of these proceedings, to keep the whole archipelago cleared of its population invites but does not require scrutiny because it is not connected with the governance of the Chagos Islands. It is connected with the United States’ strategic and geopolitical interests and with the United Kingdom’s support for these, both of them matters which the court recognises as solely for the judgment of ministers and – if the occasion arises – of Parliament; but these are not cognate with – indeed on the evidence they are in direct conflict with – the interests of the Chagossians. The ground recited in s.9(1) consequently fails to justify the substantive provision because it lies beyond the objects, whether expressed in terms of peace, order and good government or in terms of the legitimate purposes of colonial governance, for which ministers are entrusted by law with the use of the royal prerogative.
70.	Sir Sydney objects to any reliance by Mr Howell on other reasons. I agree that in principle a decision-maker who gives one set of reasons cannot, when challenged, come up with another set (see R v Westminster City Council, ex p Ermakov [1996] 2 All ER 302). But this is not a straightforward reasons case, and I prefer to consider the further reasons now advanced, while noting that they do not feature in the Order. 
71.	The prospective cost to the British taxpayer of resettling the next generations of the population (which the British taxpayer paid to remove) is in my view a mare’s nest. While resettlement will doubtless be difficult or even impossible without capital expenditure, it is not suggested on either side that the United Kingdom is under any obligation to fund it. As I have said, it is the bolting of the door to the Chagossians’ home, not the failure to provide transport there or to refurbish it, which is in issue. Indeed the Crown has rights as landowner which are capable, for the present, of answering any attempt to resettle there (notwithstanding a somewhat strained explanation in the evidence of why the Crown prefers not to rely on them). But to focus on this, as much as to focus on the logistics of resettlement, is to miss the point. The point is that the two Orders in Council negate one of the most fundamental liberties known to human beings, the freedom to return to one’s homeland, however poor and barren the conditions of life, and contingent though return may be on the property rights of others; and that they do this for reasons unconnected with the wellbeing of the people affected.

Legitimate expectation

72.	There is a second and separate reason why I consider that s.9 of the Constitution Order and the entire Immigration Order cannot stand. By enacting them, the Secretary of State has in my judgment impermissibly frustrated the legitimate expectation, created by his own predecessor in office, that the Chagossians would be vouchsafed a right of return. I respectfully agree with what Waller LJ says in his judgment on this subject.
73.	Although it has been developed and refined in the intervening years, the decision of this court in R v North and East Devon Health Authority, ex p Coughlan [2001] QB 213 remains the benchmark of substantive legitimate expectation. The present case falls into the third class identified by Lord Woolf CJ (§57), namely a lawfully made promise of a substantive benefit (substantive, that is, as opposed to procedural). In my judgment, applying the test set out in Coughlan, to frustrate the expectation which the Chagossians from November 2000 legitimately entertained of being at liberty one day to return to their homeland was so profoundly unfair, in the absence of relevant and overriding policy imperatives, as to be an abuse of power.
74.	I have set out the essential history earlier in this judgment. The case in favour of a legitimate expectation is a particularly strong one, because the public promise made by the Secretary of State to right the wrong exposed by the Divisional Court’s first judgment was immediately implemented by the enactment of a right of return for all belongers to the Chagos Islands. The public statement made by him made it clear that their return to the outer islands was consistent with the United Kingdom’s treaty obligations and was not conditional on feasibility. Although reference was made to the ongoing feasibility study, a preliminary study had already reported.
75.	Mr Anthony Bradley, presenting this limb of the respondent’s case, made it clear that there was no contest about the government’s entitlement to terminate the feasibility study and to decline to support a return to the islands. The challenge was to the abolition of the right of abode in the absence of proven good reason and of consultation.
76.	The statement made by way of explanation of the two Orders now under challenge cited non-feasibility of resettlement and “the availability and effective use of the Territory for defence purposes”. Leaving aside the question whether the latter was an admissible ground for abolishing the right of return, no evidence has been advanced to show that anything had changed between 2000, when there was apparently no defence problem and no insuperable issue of feasibility, and 2004. In the result, the Crown has not begun to establish an overriding imperative entitling it to frustrate the Chagossians’ expectation that they would at least continue to have the status of belongers. The two letters written by the United States’ administration for the purposes of these proceedings cannot affect this issue. The United States was not the author of the Orders in Council, and nothing has been deposed to by those who were to establish that these were new and overriding concerns which entitled the UK government to renege on its undertaking to the Chagossians. 
77.	In this situation the want of consultation hardly matters, though if it were all Mr Bancoult had left I would for my part uphold his case on this ground too.

Conclusion

78.	The unannounced withdrawal of the Chagossians’ right of return by the two Orders in Council in 2004 has been defended in court not on the ground of an ineluctable change of circumstance and policy but on the ground that, by using Orders in Council, ministers could do with impunity something which was known to be unlawful when done by Ordinance. If, as I would hold, there is no prior inhibition either under the 1865 Act or at common law upon the jurisdiction of the courts to adjudicate upon the validity of Orders in Council, the critical question is whether the instant case is a proper case for the court’s intervention. Notwithstanding the great latitude which the prerogative power of colonial governance enjoys, I consider the material Orders to have been unlawfully made, because both their content and the circumstances of their enactment constitute an abuse of power on the part of executive government. In my judgment the Divisional Court was right so to hold, albeit on differently expressed grounds. 
79.	I would dismiss the Secretary of State’s appeal.

Lord Justice Waller:

80.	I have read in draft the judgment of Sedley LJ.  I am grateful for his short history, which I gratefully adopt. I entirely agree with the view he expresses on the effect of the Colonial Laws Validity Act 1865.  There is, furthermore, much else with which I agree in his judgment so eloquently expressed.  But I would prefer to rest my agreement for upholding the decision of the Divisional Court on the particular facts of this case, which, in my view, gave rise to a legitimate expectation on the part of those represented by the respondent, for which the courts of this country in the modern era have to provide a remedy.  I would prefer to express no opinion as to the width in law of the prerogative power to remove persons from a conquered territory without the special features which existed in this case.  I would thus seek to express my agreement for this appeal being dismissed in my own words.  
81.	Sir Sydney Kentridge for the respondents puts his case in a variety of ways, the first of which involves an exploration as to the precise extent of the Queen’s prerogative when legislating via an Order in Council for a conquered or ceded colony, another of which involves seeking judicial review of the decision to legislate in the way that has been described in the judgment of Sedley LJ.
82.	In seeking to establish the extent of the Queen’s prerogative we have had to consider that question in its historical context and it seems to me that one should bear in mind the words of Lord Reid in Burmah Oil Co. Ltd v Lord Advocate [1965] AC 75 at 99 where he said:-
“As this point was not argued before your Lordships it is unnecessary to deal with it further.  So we must now take it that these demolitions were carried out by an exercise of the royal prerogative, and the question for decision is whether such an exercise of the royal prerogative gives any legal right to compensation to the persons who have suffered loss thereby.
It is not easy to discover and decide the law regarding the royal prerogative and the consequences of its exercises.  Apart from In re a Petition of Right and Attorney-General v De Keyser’s Royal Hotel Ltd, there have been no cases directly raising the matter for some centuries, and obiter dicta and the views of institutional writers and text writers are not always very helpful.  The definition of Dicey (Law of the Constitution, 10th ed., p 424), always quoted with approval: “The residue of “discretionary or arbitrary authority, which at any given time is legally left in the hands of the Crown,” does not take us very far.  It is extremely difficult to be precise because in former times there was seldom a clear-cut view of the constitutional position.  I think we should beware of looking at older authorities through modern spectacles.  We ought not to ignore the many changes in constitutional law and theory which culminated in the Revolution Settlement of 1688-89, and there is practically no authority between that date and 1915.  I am no historian but I would suppose that Maitland is as good a guide as any.  In his Constitutional History he says: “I do not wish you to think that a definite theory to the effect that while legislative power resides in kind and parliament, the so-called executive power is in the king alone, was a guiding theory of mediaeval politics.  On the contrary, the line between what the king could do without a parliament, and what he could only do with the aid of parliament, was only drawn very gradually, and it fluctuated from time to time.” (p 196)  And again: “Where is sovereignty?  I have before now given my reasons why we should not ask this question when studying the Middle Ages – why we should understand that no answer can be given.” (p 297)  So it appears to me that we must try to see what the position was after it had become clear that sovereignty resided in the King in Parliament.  Any rights thereafter exercised by the King (or the executive) alone must be regarded as a part of sovereignty which Parliament chose to leave in his hands.”
83.	Indeed I would suggest that one of the problems for us has been that the position in 1688-89 and since that date has itself been by no means clear. Thus in Campbell v Hall 1 Cowp 204, decided in 1774, the power of the Crown to legislate for a conquered colony was said by Lord Mansfield to be subject to two constraints, first by his proposition number 3 “that the articles of capitulation upon which a country is surrendered and the articles of peace by which it is ceded are sacred and inviolable ..”, and second by his proposition number 6 expressed in these terms:-
“The 6th, and last proposition, is that if the King (and when I say the King I always mean the King without the concurrence of Parliament) has a power to alter the old and to introduce new laws in a conquered country, this legislation being subordinate, that is, subordinate to his own authority in Parliament, he cannot make any new change contrary to fundamental principles: he cannot exempt an inhabitant from that particular dominion; as for instance, from the laws of trade or from the power of Parliament, or give him privileges exclusive of his other subjects and so in many other instances which might be put.”
84.	In Chitty’s Treatise on the Law of the Prerogatives of the Crown, published in 1820, these limits on the Crown’s prerogative were not doubted. Chitty in dealing with a country obtained by conquest or treaty and the King’s “exclusive prerogative power over it” said at page 29:-
“As, however, a country conquered by British arms becomes a dominion of the king in right of his Crown, it is necessarily subject to the legislature of Great Britain; and, consequently, his Majesty’s legislative power over it, as conqueror, is subordinate to his own authority in Parliament; so that his Majesty cannot make any new change contrary to fundamental principles, or exempt the inhabitants from the power of Parliament.  Nor can the King legally disregard or violate the articles on which the country is surrendered or ceded; but such articles are sacred and inviolable, according to their true intent and meaning.”
85.	But in relation to the limit said to exist by virtue of the articles of surrender, the Privy Council has consistently said that such agreements have no direct effect as a matter of municipal law see e.g.Cook v Sprigg [1899] AC 572 at 578; Vajesinghi Joravarasinghji v Secretary of State for India (1924) LR 51 IA 357 at 360-1; Hoani Te Heuheu Tukino v Aotea District Maori Land Board [1941] AC 308 at 324-5. As regards the limitation by reference to “fundamental principles” the Privy Council in Liyanage v The Queen [1967] AC 259 expressed strong views about the nature and extent of this “vague unspecified law of natural justice” and pointed out that no case within the previous 100 years had been founded on that portion of Lord Mansfield’s judgment. Thus it is when one looks at Halsbury’s Laws of England Vol 6 4th Edition 2003 Reissue,  paragraph 823, the position is stated without any apparent limitation in these terms:- 
“In a conquered or ceded colony the Crown, by virtue of its prerogative, has full power to establish such executive, legislative, and judicial arrangements as the Crown thinks fit, and generally to act both executively and legislatively, provided the provisions made by the Crown do not contravene any Act of Parliament extending to the colony or to all British possessions.”
86.	It will also be noted that in that paragraph there is no reference to the power being “for the peace, order and good governance” the words so often used in respect of a legislature provided to a colony by an order in council. Before us much time was spent examining the authorities dealing with those words as they had been construed in order to support the argument that, since the courts had construed these words as granting a very wide power, that must show that the power of the Queen’s prerogative was at least as wide. I am disinclined to get into the argument as to the extent of the prerogative because I confess to feeling that the power originally was likely to be very wide indeed insofar as it related to a “conquered or ceded colony” but, more importantly, because however wide that power the duty of the court is to examine what happened in this case through modern eyes and have regard to reality in the present age.
87.	We are no longer in the era where there is a contest between the Crown and parliament as to who has the power to do what. In that era it really was “the Crown” i.e. the sovereign, who preserved for him or herself the power to do certain things. Matters have gradually developed over the years so that now, constitutionally, the Crown never acts other than on advice of her ministers, and the decision to exercise the “royal prerogative” is actually taken, as this very case shows, by the government or by ministers individually.   
88.	Lord Roskill in CCSU v Minister for Civil Service [1985] AC 374 at 417 said this:- 
“In short the orthodox view was at that time that the remedy for abuse of the prerogative lay in the political and not in the judicial field.
But fascinating as it is to explore this mainstream of our legal history, to do so in connection with the present appeal has an air of unreality.  To speak today of the acts of the sovereign as “irresistible and absolute” when modern constitutional convention requires that all such acts are done by the sovereign on the advice of and will be carried out by the sovereign’s ministers currently in power is surely to hamper the continual development of our administrative law by harking back to what Lord Atkin once called, albeit in a different context, the clanking of mediaeval chains of the ghosts of the past see United Australia Ltd v Barclays Bank Ltd [1941] AC 1, 29.  It is, I hope, not out of place in this connection to quote a letter written in 1886 by the great legal historian F W Maitland to Dicey himself: “The only direct utility of legal history (I say nothing of its thrilling interest) lies in the lesson that each generation has an enormous power of shaping its own law”: see Richard A Cosgrove, The Rule of Law: Albert Venn Dicey, Victorian Jurist (1980) p 177.  Maitland was in so stating a greater prophet than even he could have foreseen for it is our legal history which has enabled the present generation to shape the development of our administrative law by building upon but unhampered by our legal history.
My Lords, the right of the executive to do a lawful act affecting the rights of the citizen, whether adversely or beneficially, is founded upon the giving to the executive of a power enabling it to do that act.  The giving of such a power usually carries with it legal sanctions to enable that power if necessary to be enforced by the courts.  In most cases that power is derived from statute though in some cases, as indeed in the present case, it may still be derived from the prerogative.  In yet other cases, as the decisions show, the two powers may coexist or the statutory power may by necessary implication have replaced the former prerogative power.   If the executive instead of acting under a statutory power acts under a prerogative power and in particular a prerogative power delegated to the respondent under article 4 of the Order in Council of 1982, so as to affect the rights of the citizen, I am unable to see, subject to what I shall say later, that there is any logical reason why the fact that the source of the power is the prerogative and not statute should today deprive the citizen of that right of challenge to the manner of its exercise which he would possess were the source of the power statutory.  In either case the act in question is the act of the executive.  To talk of that act as the act of the sovereign savours of the archaism of past centuries.  In reaching this conclusion I find myself in agreement with my noble and learned friends Lord Scarman and Lord Diplock whose speeches I have had the advantage of reading in draft since completing the preparation of this speech.
But I do not think that that right of challenge can be unqualified.  It must, I think, depend upon the subject matter of the prerogative power which is exercised.  Many examples were given during the argument of prerogative powers which as at present advised I do not think could properly be made the subject of judicial review.  Prerogative powers such as those relating to the making of treaties, the defence of the realm, the prerogative of mercy, the grant of honours, the dissolution of Parliament and the appointment of ministers as well as other are not, I think, susceptible to judicial review because their nature and subject matter are such as not to be amenable to the judicial process.  The courts are not the place wherein to determine whether a treaty should be concluded or the armed forces disposed in a particular manner or Parliament dissolved on one date rather than another.”
89.	He may not, I accept, have had in mind the exercise of the prerogative in legislating for a ceded or conquered colony. But if one has regard to what really happened in this case it seems to me one has the following picture – a picture that reflects the reality that Lord Roskill had in mind.
90.	The Divisional Court reached its decision in favour of the Ilois on 3 November 2000. This, it should be said, was after the completion of a preliminary Feasibility Study produced on 20 June 2000. That was the context for the Foreign Secretary (Mr Robin Cook MP) to issue the following written statement:- 
“I have decided to accept the Court’s ruling and the Government will not be appealing.
The work we are doing on the feasibility of resettling the Ilois now takes on a new importance.  We started the feasibility work a year ago and are now well underway with phase two of the study.
Furthermore, we will put in place a new Immigration Ordinance which will allow the Ilois to return to the outer islands while observing our Treaty obligations.
This Government has not defended what was done or said thirty years ago.  As Lord Justice Laws recognised, we made no attempt to conceal the gravity of what happened.  I am pleased that he has commended the wholly admirable conduct in disclosing material to the Court and praised the openness of today’s Foreign Office.”
91.	That statement does not suggest that a decision was conditional on any further Feasibility Study or indeed that the decision was in any way conditional. It gave the clear impression that any dispute was over and that the Ilois would be able to return long-term, or at the very least that they would be allowed to return until there was some radical change in circumstances unforeseeable at that time.
92.	It further reflects the reality that the Government, i.e. the executive, had decided to put in place a new Ordinance. 
93.	There was no change of circumstance, save it might be said that there were thereafter further phases of the Feasibility Study conducted with the co-operation of the Ilois culminating in a report published on 10 July 2002. That report concluded that while resettlement on a short term subsistence basis was possible, long term resettlement would be precarious and “costly”. Whether it would be costly to the United Kingdom government would depend whether there was any obligation on the United Kingdom government to incur expenditure if the government allowed the Ilois to return. Mr Howell strongly denied that the United Kingdom would have any such obligation. Indeed the Ilois had lost the litigation before Ouseley J. If one simply posed the question whether the Ilois should be allowed to return if they chose to do so at their own risk, this could not be affected by the conclusion of this Feasibility Study. In relation to that simple question - should the Ilois be allowed to return if they wanted to and at their own risk - nothing had changed between November 2000 and June 2004.
94.	However in June 2004 the government took a decision that the Ilois were no longer to be allowed to return to the Outer Islands without a permit. That is to say they took a decision to go back on the statement of Robin Cook that there would be in place an Ordinance that the Ilois should be quite free to return to the Outer Islands. No explanation was given to those representing the Ilois, and thus no-one sought to suggest a reason to the Ilois why a change of heart was taking place.
95.	Two Orders in Council were accordingly drafted by ministers to give effect to that decision. The drafts were placed before Her Majesty in Council on 10 June 2004 and on the advice of her ministers and, without any debate in Council or at all, the Queen made the Orders in Council as she was constitutionally obliged to do.
96.	On 15 June 2004 the Parliamentary Secretary of State for Foreign and Commonwealth Affairs issued a statement  in the following terms:-
“93. . . .	anything other than short-term resettlement on a purely subsistence basis would be highly precarious and would involve expensive underwriting by the UK Government for an open-ended period – probably permanently. Accordingly, the Government considers that there would be no purpose in commissioning any further study into the feasibility of resettlement; and that it would be impossible for the Government to promote or even permit resettlement to take place. After long and careful consideration, we have therefore decided to legislate to prevent it.
Equally, restoration of full immigration control over the entire territory is necessary to ensure and maintain the availability and effective use of the Territory for defence purposes, for which it was in fact constituted and set aside in accordance with the UK's treaty obligations entered into almost 40 years ago. Especially in the light of recent developments in the international security climate since the November 2000 judgment, this is a factor to which due weight has had to be given.
It was for these reasons that on 10 June 2004 Her Majesty made two Orders in Council, the combined effect of which is to restore full immigration control over all the islands of the [BIOT]. These controls extend to all persons, including members of the Chagossian community.
The first of these two Orders replaces the existing Constitution of the Territory and makes clear, as a principle of the Constitution, that no person has the right of abode in the Territory or has unrestricted access to any part of it. The second Order replaces the existing Immigration Ordinance of the Territory and contains the detailed provisions giving effect to that principle and setting out the necessary immigration controls. These two Orders restore the legal position to what it had been understood to be before the High Court decision of 3 November 2000.”
97.	It will be noted first that the statement reflects reality - “we have therefore decided to legislate. . . ”.  Second it is quite unclear where the obligation to underwrite comes from – any legal obligation was denied strenuously by Mr Howell and the statement does not address the simple question whether there was any justification for banning the Ilois from returning entirely at their own risk.
98.	A further statement in the House of Commons from the Under Secretary of State included these words:-
“94 . . .
The judgment, which was given in November 2000, held that the provision of the 1971 ordinance was invalid to the extent that it excluded the Chagossians from the whole territory. At that stage, the Government decided to accept that finding and not appeal, and the 1971 ordinance was replaced by a new one, which allowed the Chagossians to return and reside in any part of the territory, except, for defence reasons, Diego Garcia. A reasonable question at that juncture would have been, "What has changed between now and then?" That is a legitimate question to which I will try to respond.
…
Due to the fact that settlement is not feasible, the Government decided after long and careful consideration – that was genuinely the case – to legislate to prevent it. Equally, however, legislation to restore full immigration control over the entire territory is also necessary, and I do not absolve ourselves from responsibility for this so as to ensure and maintain the availability and effective use of the territory for defence purposes for which it was constituted and set aside in accordance with the UK's treaty obligations entered into almost 40 years ago.”
99.	It seems to me that the question is not so much whether the Queen had the power to make the Orders in Council or (at least as the first question) whether the decision made in Council is itself judicially reviewable, but whether there is any procedural impropriety in the making of the decision of the ministers to produce Orders in Council, whether that is judicially reviewable, and if so, what effect that can have on the Orders In Council produced. If the decision made to produce an order in council is reviewable [and that is the critical question which I have yet to address and to which I must return], as I would see it there is no complication as to whether the Orders in Council should be judged by reference to the interests of the United Kingdom or the interests of BIOT. The position is surely much more straightforward. The Foreign Minister made a statement holding out to a certain body of people, the Ilois, that they would be allowed to return to the Outer Islands. No justification or reason has been provided as to why that promise should now be withdrawn. R v North and East Devon Health Authority ex p Coughlan [2001] QB 213 helpfully analyses the types of statements and promises that cannot be ignored and demonstrates the different remedies that may flow. Paragraphs 55 to 58 of the judgment of the court say:-
“55. In considering the correctness of this part of the judge’s decision it is necessary to begin by examining the court’s role where what is in issue is a promise as to how it would behave in the future made by a public body when exercising a statutory function.  In the past it would have been argued that the promise was to be ignored since it could not have any effect on how the public body exercised its judgment in what it thought was the public interest.  Today such an argument would have no prospect of success, as Mr Goudie and Mr Gordon Accept.
56. What is still the subject of some controversy is the court’s role when a member of the public, as a result of a promise or other conduct, has a legitimate expectation that he will be treated in one way and the public body wishes to treat him or her in a different way.  Here the starting point has to be to ask what in the circumstances the member of the public could legitimately expect.  In the words of Lord Scarman in In re Findlay [1985] AC 318, 338, “But what was their legitimate expectation?”  Where there is a dispute as to this, the dispute has to be determined by the court, as happened in In re Findlay.  This can involve a detailed examination of the precise terms of the promise or representation made, the circumstances in which the promise was made and the nature of the statutory or other discretion.
57. There are at least three possible outcomes.  (a) The court may decide that the public authority is only required to bear in mind its previous policy or other representation, giving it the weight it thinks right, but no more, before deciding whether to change course.  Here the court is confined to reviewing the decision on Wednesbury grounds (Associated Provincial Picture Houses Ltd v Wednesbury Corpn [1948] 1 KB 223).  This has been held to be the effect of changes of policy in cases involving the early release of prisoners: see In re Findlay [1948] AC 318; R v Secretary of State for the Home Department, Ex p Hargreaves [1997] 1 WLR 906.  (b) On the other hand the court may decide that the promise or practice induces a legitimate expectation of, for example, being consulted before a particular decision is taken.  Here it is uncontentious that the court itself will require the opportunity for consultation to be given unless there is an overriding reason to resile from it (see Attorney General of Hong Kong v Ng Yuen Shiu [1983] 2 AC 629) in which case the court will itself judge the adequacy of the reason advanced for the change of policy, taking into account what fairness requires.  (c) Where the court considers that a lawful promise or practice has induced a legitimate expectation of a benefit which is substantive, not simply procedural, authority now establishes that here too the court will in a proper case decide whether to frustrate the expectation is so unfair that to take a new and different course will amount to an abuse of power.  Here, once the legitimacy of the expectation is established, the court will have the task of weighing the requirements of fairness against any overriding interest relied upon for the change of policy. 
58. The court having decided which of the categories is appropriate, the court’s role in the case of the second and third categories is different from that in the first.  In the case of the first, the court is restricted to reviewing the decision on conventional grounds.  The test will be rationality and whether the public body has given proper weight to the implications of not fulfilling the promise.  In the case of the second category the court’s task is the conventional one of determining whether the decision was procedurally fair.  In the case of the third, the court has when necessary to determine whether there is a sufficient overriding interest to justify a departure from what has been previously promised.”
100.	If the procedure whereby a decision taken to introduce the Orders in Council in 2004 is reviewable, it seems to me that Robin Cook’s statement falls within the third category identified by the court. In my view to frustrate the expectation of the Ilois would be so unfair, that to take a new and different course would amount to an abuse of power, unless there is an overriding interest to justify a departure from what has previously been promised. I accept that in this context the fact that the promise was given to the Ilois and that breaking the promise would involve keeping an entire population from its homeland, for reasons which have no justification, forms the context in which that promise was given.  I would however, (again, I stress, on the basis that the decision was reviewable at all) prefer to express no view on whether the court would be bound to hold (as Sedley LJ suggests in paragraph 67) that any decision to remove persons from a conquered or ceded territory, albeit their homeland, for reasons unconnected with their wellbeing, would be unlawful.
101.	The critical question is whether the procedure by which the decision of the ministers to introduce the Orders in Council in 2004 was carried out, is reviewable and whether, if so, there is any power to set aside those Orders in Council. 
102.	There is no suggestion that Ministers were dealing in one of those areas identified by Lord Roskill where the courts simply should not be concerned such as national security. The only argument in favour of the court not having the power to interfere has to be on the basis that an Order in Council is legislation and there is some immunity which protects the minsters responsible for the decision to legislate and the Queen in council from interference by the court.
103.	It is well settled that Parliament is sovereign and the role of the courts is confined to interpreting and applying what Parliament has enacted. Furthermore no-one can impugn what goes on in Parliament. The courts will not allow any challenge to be made to what is said or done within the walls of Parliament:  see for example the Opinion of the Privy Council in Poitier and others v The Methodist Church of the Bahamas [2000] UKPC 31 delivered 26th July 2000 [tab 62 in the bundle of authorities]. An attempt to impugn legislation on the basis that a minister had made a statement outside or inside  parliament which gave a legitimate expectation that such legislation would not be introduced would be doomed to failure.
104.	However, so far as subsidiary legislation is concerned, the position appears to be different. In Reg v Health Secretary, ex parte U.S. Tobacco [1992] 1 QB 353 the Divisional Court set aside certain regulations made under section 11 of the Consumer Protection Act 1987 on the grounds that fairness following the government’s dealings with the applicants had required disclosure, during the consultation process, of certain scientific advice. The regulations had been laid before Parliament and had come into force but that did not prevent the Divisional Court quashing the regulations, Taylor LJ saying this at the conclusion of his judgment:- 
“Although the Regulations were subject to annulment by negative resolution of the House of Commons but were not so annulled, Parliament would be concerned only with the objects of the Regulations and would be unaware of any procedural impropriety. It is therefore to the courts, by way of judicial review, that recourse must be had to seek a remedy.”
105.	Mr Howell draws attention to the fact that in the above case there was a statutory duty to consult, but in the judgment there is no suggestion that it was that statutory duty which led to the conclusion that the regulations would be set aside.  The conclusion flowed from the unfairness and the failure to treat with candour.
106.	The question is where in the spectrum should an Order in Council fall in the modern era? Should it be categorised with primary legislation passed through Parliament or with secondary legislation subject to a negative resolution or in some other category? So far as legislation passed in Parliament is concerned, there is an opportunity for debate and scrutiny. So far as subsidiary legislation in the form of regulations is concerned there is little opportunity for debate but at least there is the negative resolution procedure. So far as Orders in Council are concerned there is simply no opportunity for debate at all and no opportunity for scrutiny. It involves a minister acting without any constraint. Indeed the Crown may be doing something that, if she only knew the true position, she would prefer not to do, and yet it is then said that the government can hide behind the “Crown’s prerogative”. 
107.	In the modern era I do not believe that position is tenable. If regulations can be set aside for procedural impropriety then the more so should decisions to act by Order in Council. Since the power of the Crown to legislate by Order in Council flows from the common law, it should if anything be clearer that the court has the power to interfere for procedural impropriety in that context than in the context where regulations have been placed before parliament and passed by virtue of the negative resolution procedure. 
108.	I would uphold the decision of the Divisional Court to set aside those parts of the Orders in Council which had the effect of reversing the position adopted by the government in November 2000.

Sir Anthony Clarke MR:

109.	I agree that this appeal should be dismissed.  I add a few words of my own because of the importance of the legal questions in issue and because I take what may be a somewhat narrower view than Sedley LJ on one aspect of the case.
110.	At the end of the oral argument I intended to address in detail what was meant by the expression ‘peace order and good government’ because it seemed to me that Mr Howell’s submissions gave it too wide a meaning.  However, interesting though that question is, I have reached the conclusion that it is not necessary to address the question in order to decide the appeal.
111.	In my opinion the time has come to recognise that the principle stated by Lord Scarman in Council of Civil Service Unions v Minister for the Civil Service [1985] 374 at 407 applies to all exercises of the royal prerogative, including all Orders in Council.  Sedley LJ has quoted the whole passage at [40]; so I set out here only the key parts of it, omitting the various references:

“My Lords, I would wish to add a few, very few, words on the reviewability of the exercise of the royal prerogative.  Like my noble and learned friend Lord Diplock, I believe that the law relating to judicial review has now reached the stage where it can be said with confidence that, if the subject matter in respect of which prerogative power is exercised is justiciable, that is to say if it is a matter upon which the court can adjudicate, the exercise of the power is subject to review in accordance with the principles developed in respect of the review of the exercise of statutory power.  Without usurping the role of legal historian, for which I claim no special qualification, I would observe that the royal prerogative has always been regarded as part of the common law, ... and that Sir Edward Coke had no doubt that it was subject to the common law …  [In the] Case of Proclamations … he declared … that “the King hath no prerogative, but that which the law of the land allows him.”  It is, of course, beyond doubt that in Coke's time and thereafter judicial review of the exercise of prerogative power was limited to inquiring into whether a particular power existed and, if it did, into its extent: …  But this limitation has now gone, overwhelmed by the developing modern law of judicial review: … Just as ancient restrictions in the law relating to the prerogative writs and orders have not prevented the courts from extending the requirement of natural justice, namely the duty to act fairly, so that it is required of a purely administrative act, so also has the modern law, a vivid sketch of which my noble and learned friend Lord Diplock has included in his speech, extended the range of judicial review in respect of the exercise of prerogative power.  Today, therefore, the controlling factor in determining whether the exercise of prerogative power is subject to judicial review is not its source but its subject matter.”
Lord Roskill said much the same in the passage from the CCSU case quoted by Waller LJ at [88] above.
112.	In the CCSU case, it was not the Order in Council itself which was challenged but an instruction given under it.  However, as I read the passage just quoted, Lord Scarman was not drawing a distinction in principle between the exercise of the prerogative in an Order in Council and the exercise of the prerogative in an instruction given under it.  Each is an example of the exercise of the prerogative.  If Lord Scarman’s reasoning is applied to Orders in Council of the kind under challenge in the instant case, they are subject to judicial review in the same way as other Orders in Council.  For the reasons given by both Sedley and Waller LJJ, I can see no reason why the reasoning should not be so applied.  
113.	Let it be assumed that historically the power of the sovereign was entirely (or almost entirely) unfettered, so that he or she had the same powers as Parliament now has to make laws for ceded and conquered territories (or anywhere else).  It does not follow that the Queen still has those unfettered powers to legislate by Order in Council.  I agree with Sedley and Waller LJ that she does not.
114.	The principal reasons are those given by Sedley LJ at [32] above by reference to quotations from Anson and Lord Diplock.  Thus Anson said in the third edition of his Law and Custom of the Constitution:
“The position of affairs has been reversed since 1714.  Then the King or Queen governed through Ministers, now Ministers govern through the instrumentality of the Crown.”
And Lord Diplock said in the CCSU case that, where the prerogative is the source of the decision-making power, in constitutional practice the power is generally exercised by those holding ministerial rank.      
115.	That was precisely what happened on the facts of this case.  As Waller LJ puts it at [92] above, it was the executive not the Crown that decided to put the 2004 Orders in place.  It did so without consulting the Chagossians or anyone on their behalf and without even informing, let alone seeking the advice of, Parliament.  Moreover, although the relevant orders were entitled Orders in Council, the Privy Council, as distinct from the executive, was not consulted before they were formally made by the Queen, who was bound by constitutional theory and practice to make them.  It seems to me that if, as the House of Lords held was the position in the CCSU case, the exercise of the prerogative in that case was in principle susceptible to judicial review, so should the Orders in Council in the instant case.  A view of the case through the ‘modern spectacles’ of which Lord Reid spoke in the Burmah Oil case (quoted at [82] above) leads precisely to that conclusion. 
116.	A further consideration leading to the same conclusion is that discussed by Sedley LJ at [34] above, where he considers whether a prohibiting order could have been made to prevent him from laying the draft orders before the Queen for her approval.  I agree with him that, in principle, such an order could be made and that the decision in M v Home Office [1994] 1 AC 377 supports that conclusion.
117.	I also agree with Sedley LJ for the reasons he has given that there is nothing in the Colonial Laws Validity Act 1865 which leads to any other conclusion.  As I see it, the only basis upon which it might be held that the Orders in Council were not susceptible to judicial review, would be on the ground, as Lord Scarman put it, of subject matter.  Thus, if the subject matter of the Orders in Council or the nature of the review sought were such as to make the claim either non-justiciable or justiciable only on narrow grounds, the court would or might not entertain it: see eg per Lord Roskill in the CCSU case at page 418 (quoted by Sedley LJ at [44] above) and, recently, R (Gentle) v The Prime Minister [2006] EWCA Civ 1690 at [26] et seq.                            
118.	It is not suggested by Mr Howell that there is anything in the Orders in Council or in the nature of the claim for judicial review which makes the issues non-justiciable on the grounds of subject matter.  It is not, for example, said that the claim involves issues of national security which prevent the court from determining it.  This is by way of contrast to the position in the CCSU case itself.
119.	On the assumption that, as in my opinion is the case, both the decision to make the Orders in Council and the Orders in Council themselves are subject to judicial review, the question is whether the Divisional Court was wrong to hold that they should be quashed.  My conclusion is that the answer to that question is no, essentially for the reasons given by Waller LJ in his judgment and for the reasons given by Sedley LJ at [72] to [76] of his judgment.
120.	Waller LJ has set out in detail the public statement made by the then Foreign Secretary in November 2000 in immediate response to the decision of the Divisional Court quashing the 1971 Ordinance.  I agree with Waller LJ in particular:
i)	that the statement gave, as he puts it at [91], the clear impression that the Ilois would be able to return long-term, or at the very least would be allowed to return unless there was some radical change in circumstances;
ii)	that that statement gave rise to a legitimate expectation that that would remain the position and that the principles stated at [55] to [58] of R v North and East Devon Health Authority ex p Coughlan [2001] QB 213 apply to the circumstances in which the executive could lawfully resile from the position stated in November 2000 (see [99] above); and 
iii)	that the statement falls within the third category identified at [57] in the Coughlan case (see [100] above) because this is a case in which a lawful promise has induced a legitimate expectation of a substantive benefit and to frustrate the expectation “is so unfair that to take a new and different course will amount to an abuse of power”.    
121.	It follows, as I see it, that the executive could only change the policy stated in November if, in the words of [57] in Coughlan, there was some overriding interest relied upon for the change of policy.  The difficulty faced by the appellant is that no relevant change of circumstances is alleged.  The circumstances in 2004 were essentially the same as in 2000.  In this regard I agree in particular with [73] to [76] in Sedley LJ’s judgment.  In short, I agree with Sedley and Waller LJJ that the decision to make the 2004 Orders and the making of the Orders were abuses of power on this ground.  For these reasons I agree that the appeal should be dismissed.
122.	The position would be at least potentially different but for the public statements made in November 2000.  However, even absent those statements, it is my opinion that the 2004 Orders would have been an abuse of power.  I recognise the rights of the Chagossians but I would not go so far as to say, as the argument summarised by Sedley LJ at [61] does, that the Crown’s common law powers do not extend to exiling a whole population.  In making any decision the Crown (ie the executive) must of course have regard only to relevant considerations and thus not to irrelevant considerations and it must act rationally.  It follows that it must have regard to the interests of the Chagossians, including of course their rights, before making any order which affects them.  However, I am not for my part persuaded that it cannot also have regard to the interests of the United Kingdom and, if it can, I would not accept that it must have sole (or perhaps even primary) regard for the interests of the Chagossians.  As I see it at present, it should have regard to the interests of both the Chagossians and of the United Kingdom and reach a rational decision on any question which arises for decision.                                           
123.	Whether those views are correct or not, I agree with Sedley LJ that the 2004 Orders were an abuse of power because they did not have proper regard for the interests of the Chagossians.  In particular, I agree with his conclusions at [62]:
“The prospective cost to the British taxpayer of resettling the next generations of the population (which the British taxpayer paid to remove) is in my view a mare’s nest. While resettlement will doubtless be difficult or even impossible without capital expenditure, it is not suggested on either side that the United Kingdom is under any obligation to fund it. As I have said, it is the bolting of the door to the Chagossians’ home, not the failure to provide transport there or to refurbish it, which is in issue. Indeed the Crown has rights as landowner which are capable, for the present, of answering any attempt to resettle there (notwithstanding a somewhat strained explanation in the evidence of why the Crown prefers not to rely on them). But to focus on this, as much as to focus on the logistics of resettlement, is to miss the point. The point is that the two Orders in Council negate one of the most fundamental liberties known to human beings, the freedom to return to one’s homeland, however poor and barren the conditions of life and contingent though entry may be on the property rights of others; and that they do this for reasons unconnected with the wellbeing of the people affected.”
Although I can imagine circumstances in which it would be possible for the executive rationally to conclude that the freedom to return to a person’s home territory should be removed, I agree with Sedley LJ that this is not such a case.
124.	It follows that the appeal will be dismissed, although I would like to say on behalf of all members of the court how much we admired the learning and research which went into the arguments on both sides.