Bertrice Pompe, R (on the application of) v The Secretary of State for Foreign, Commonwealth and Development Affairs

This matter comes before the court on the claimants’ request for an oral hearing to renew their application for permission for their claim to proceed to a full hearing, following refusal on the papers by the single judge.

There are two sets of proceedings that have been listed to be heard together since the issues in both claims are materially identical. The claimants in both cases seek to challenge decisions made by the defendant, the Secretary of State for Foreign, Commonwealth and Development Affairs, in their role as a decision-maker over the British Indian Ocean Territory (“the BIOT”) and domestic territory. In claim AC-2025-LON-001642, Ms Bertrice Pompe initially sought urgent interim relief in the out of hours interim applications court on 21 May 2025. A temporary order was made at 2.25am on 22 May 2025 preventing the defendant from (1) taking any conclusive or legally binding steps to conclude its negotiations concerning the possible transfer of the BIOT to a foreign government or bind itself as to the particular terms of any such transfer; (2) disposing of the BIOT and (3) requiring him to maintain the jurisdiction of the United Kingdom of Great Britain over the BIOT until a further hearing at 10.30am later that day. The temporary order was discharged later that day (around noon on 22 May 2025) by Chamberlain J who made orders and directions for lodging and filing of the statement of facts and grounds and documents necessary for the permission stage. Once the injunction had been lifted a treaty between the Government of the United Kingdom (“HMG”) and the Republic of Mauritius (“GoM”) was signed by the respective countries’ Prime Ministers which provides for future sovereignty over the BIOT shortly after noon on 22 May 2025 (“the Treaty”).

In claim AC-2025-LON-002073 brought by father and son: Mr Louis Michel Mandarin and his son Mr Louis Misley Mandarin (“the Mandarin Claimants” and where necessary to distinguish between them “Mr Mandarin snr” and “Mr Mandarin jnr”) proceedings were issued on 24 June 2025. The three claimants are now British citizens and were either born in the Chagos Archipelago (“the Islands”) or in Mauritius following their families’ displacement from the Islands and all identify and describe themselves as Chagossian.

The defendant’s decisions, which are also alleged as ongoing failures, are alleged to be unlawful on six grounds:

The claims are resisted by the defendant. As well as disputing the specific issues raised in each ground, the defendant argues that although the claims are ostensibly drafted as a collateral attack, the challenge is in fact a direct challenge to the Treaty which is an international treaty made by HMG and the Bill to implement the Treaty in domestic law currently before parliament, when there is no authority or principle that can be relied on to compel HMG to exercise prerogative powers of treaty making and international relations in a particular way. In any event, the issues now sought to be raised have been conclusively decided in earlier litigation R (Hoareau and Bancoult (No.5)) v. Secretary of State for Foreign and Commonwealth Affairs EWCA Civ 1010 (‘Bancoult (No. 5) CA’).

There is a long and shameful history to the treatment of the inhabitants of the Chagos Islands recorded in the findings of a number of judgments in the jurisdiction of England and Wales and the European Court of Human Rights (“ECtHR”) in various proceedings that have been brought since the 1970s. In brief summary and insofar as is relevant for the purposes of this application, the material facts are these. The remote and isolated Chagos Islands are located in the middle of the Indian Ocean approximately 1,000 miles from southwest of the southern tip of India, 2,200 miles east of Mombasa, Kenya, about 1,000 miles east of the main island in the Seychelles and around 800 miles north-east of Port Louis in Mauritius. The largest of the around 60 islands in the archipelago is Diego Garcia and other significant sized islands includes Peros Banhos and Salomon islands. All the Islands were uninhabited when they were first visited by Malaysians, Arabs and Portuguese in the 18^th century.

The first settlers were probably French and began coconut (copra) plantations and the Chagos Islands became a French colony. It was ceded by France to the Crown by the Treaty of Paris in 1814 and was administered by the Crown from Mauritius as part of the “Lesser dependencies” (together with St Brandon and Agalega which lie 1,000 miles from the Chagos Islands halfway between Mauritius and the Seychelles). By the beginning of the 20th century there were some 426 families of African, Malagasy and Indian origin who mostly considered themselves to be permanent residents. Many had initially arrived as slaves but following the abolition of slavery in 1833 had continued to work in the plantations as freed labour and remained in the colony. There was no electricity, sanitation or other infrastructure beyond a small dispensary, very basic medical attention, limited educational facilities and a priest. Those who worked on the copra plantations received a small monetary wage, but the chief payment was barter. Most families fished, had small kitchen gardens and reared chickens and ducks. Over the years there was some movement of workers between the Chagos Islands and Mauritius and the Seychelles under contract to the plantation company, whilst other inhabitants went back several generations of living on the Islands. By the early 1960s the Islands’ population was in decline due to low wages, monotonous work, lack of facilities, the remoteness of the Islands and their distance from Mauritius and the Seychelles. By 1962 the population was less than a thousand settled on the three main groups of islands and none of the outer islands had been inhabited for years.

In 1964 discussions began in earnest between HMG and the United States Government (“USG”) over the establishment of United States defence facilities in the Indian Ocean which was and is still seen as strategically important. The USG asked HMG for a territory with no inhabitants and negotiations started for the UK to lease Diego Garcia to the US for this purpose. It was envisaged from the beginning that any inhabitants would be transferred or resettled. In November 1965 the UK reached agreement on the detachment of the Islands from Mauritius and the Islands became part of the BIOT by the BIOT Order 1965 (SI 1965/1920). No right of abode had been recognised in the BIOT.

An agreement between HMG and USG was duly reached on 30 December 1966 in an exchange of notes for the BIOT to be available “for the needs of both governments for defence” comprising 50 years initially followed by 20 years unless notice to terminate was given (“the 1966 Agreement”). The current position is that the agreement continues until 2036.

Between 1966 and 1972 HMG relocated all Chagossians to Mauritius and the Seychelles. The treatment of the Chagossians has been described in earlier court judgments as “shameful”, amounting to the “pauperisation and expulsion of the weak in the interests of the powerful” (Chagos Islanders v AG [2004] EWCA Civ 997 at [6]) and that the exile was achieved with a callous disregard for the interests of Chagossians (see R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (No. 2) [2009] AC 453 at [10]). One telling detail to emerge was a private Foreign Office memorandum of 24 August 1966 describing the inhabitants of the Islands as “some few Tarzans or Man Fridays, whose origins are obscure, and who are being hopefully wished on to Mauritius etc.” (Footnote: ¹) As Mr Rule KC explained, the Chagos Islanders have now been in exile since being forcibly removed over 50 years ago. The witness statement of Mr Mandarin snr gives a chilling account of the upheaval from his family’s expulsion from their homeland and their struggles in Mauritius. HMG has since expressed its sincere regret about the manner in which the Chagossians were removed, as was reiterated through Mr Beal KC at the hearing before me.

Title in the Islands has at all material times vested in the Crown in right of the BIOT and since 1967 the land in the BIOT has also been land vested in the Crown. The inhabitants of Diego Garcia were first removed to the outer islands, Salomon Islands and Peros Banhos. Following the coming into force of the Immigration Ordinance 1971 No. 1 of 1971 by the BIOT Commissioner in April 1971 (“the Immigration Ordinance 1971”) it became unlawful for someone to enter or remain in the BIOT without a permit and it provided for the Commissioner to make an order directing the removal of a person without a permit to enter or remain on the Islands. Between July 1971 to May 1973 the entire population of the Islands, none of whom had permits, either left or were removed and relocated in the Seychelles and Mauritius – those displaced persons included Mr Mandarin snr. Chagossians were given a limited right via a BIOT permit to be able to visit for short-term cultural or familial visits including to graves of relatives. The Chagossians and, since 2022 their descendants born outside the BIOT, are also entitled to be recognised as British citizens.

Most of those displaced to Mauritius did not fare well and were completely unprepared for life away from the Islands as recorded in a number of judgments of the courts. For example:

“ 50. The [Chagossians] were experienced in working on coconut plantations but lacked other employment experience. They were largely illiterate and spoke only Creole. Some had relatives with whom they could stay for a while; some had savings from their wages; some received social security, but extreme poverty routinely marked their lives. Mauritius already itself experienced high unemployment and considerable poverty. Jobs, including very low paid domestic service, were hard to find. The [Chagossians] were marked by their poverty and background for insults and discrimination. Their diet, when they could eat, was very different from what they were used to. They were unused to having to fend for themselves in finding jobs and accommodation and they had little enough with which to do either. The contrast with the simple island life which they had left behind could scarcely have been more marked.

51.

There was no resettlement scheme when they arrived…” (Chagos Islanders v AG [2003] EWHC 2222 (QB))

And

“154.

Whatever view might be taken of the importance of the strategic defence aims underlying the creation of BIOT, the evacuation of the islands and the establishment of the base on Diego Garcia, some who had lived there for generations were uprooted from the only way of life which they knew and were taken to Mauritius and the Seychelles where little or no provision for their reception, accommodation, future employment and well-being had been made. Ill- suited to their surroundings, poverty and misery became their common lot for years. The Chagossians alone were made to pay a personal price for the defence establishment on Diego Garcia, which was regarded by the UK and US Governments as necessary for the defence of the West and its values. Many were given nothing for years but a callous separation from their homes, belongings and way of life and a terrible journey to privation and hardship. Such arrangements as were made in the early 1970s did not take effect for several years and came too little and too late to alleviate their problems. An eventual accord in 1982, driven by litigation, produced an offer which was intended to improve their sad conditions, but which was not evidently generous. Their poverty, sadness and sense of loss and displacement impel their continuing desire to return to the islands which were their home.” (Chagos Islanders v AG [2003] EWHC 2222 (QB))

The treatment of the Chagossians has been compared to the Highland Clearances conducted in the second quarter of the nineteenth century. Whilst there has been trenchant criticism of the treatment of the Chagossian people in the legal judgments, including the observation that legal powers designed for the governance of the Islands were used for the illicit purpose of depopulating them (Bancoult (No. 5) at [4]) and the manner of their displacement in the 1960s-70s, the courts in this country and the European Court of Human Rights have not upheld their claimed right of abode or right of return to the Islands.

Legal proceedings against HMG commenced in 1975 by Michel Ventacassen and others concerning the expulsions were settled in 1978 on payment by HMG of £4 million to GoM to assist the Chagossians who had been displaced to Mauritius.

In Orders made in 2000, for a brief period from 2000-2004, Chagossians were allowed to return to any of the Islands, apart from Diego Garcia, without the need for an entry permit. But with the BIOT (Constitution) Order 2004 and the BIOT (Immigration) Order 2004 (together “the 2004 Orders”) the position reverted to the 1971 position and removed any possibility of abode and disentitled the Chagossians from entry or presence on any of the islands in the Chagos Archipelago without specific permission. It remains the case that Chagossians have no right of abode in the Islands. There is no settled civilian population in the BIOT nor any infrastructure to support human occupation in any of the islands apart from Diego Garcia which is used as a staging area for US military operations and houses a US naval base. A legal challenge to the 2004 Orders failed (see below).

From time to time HMG has considered afresh the possibility of allowing Chagossians to resettle the Islands, but on each occasion has decided not to. In the process of its reconsiderations on the future of the Islands it has sought out the opinions of Chagossians. For example, in November 2009 a consultation preceded the declaration of a marine protected area (“MPA”) around the Islands. Following an announcement in 2012 the Secretary of State announced a policy review to consider afresh the possibility of resettling the Chagossian population in the BIOT. KPMG conducted a feasibility study concluded in January 2015 to consider possible resettlement which included consultation with the Chagossian communities in Mauritius, Seychelles, Manchester, Crawley and London. Further consultation with Chagossians took place in the autumn of 2015. HMG decided not to support resettlement but made additional funding available to displaced Chagossians in its decision of 16 November 2016 (“the 2016 resettlement decision”). The decisions were subject to legal challenge, discussed below.

On 3 November 2022, the then Secretary of State made a written ministerial statement, which explained that the UK and Mauritius had decided to begin negotiations on the exercise of sovereignty over the BIOT/Chagos Archipelago, “to secure an agreement on the basis of international law to resolve all outstanding issues, including those relating to the former inhabitants of the Chagos Archipelago”. This would allow HMG and Mauritius to work more closely together in future and both governments reiterated that any agreement would “ensure the continued effective operation of the joint UK/US military base on Diego Garcia, which plays a vital role in regional and global security”. At that stage it was hoped that an agreement could be reached by early 2023, as expressed by the then Secretary of State in the written ministerial statement.

The Secretary of State announced shortly thereafter that he intended to engage with Chagossian groups as negotiations progressed between the UK and Mauritius and an engagement even took place on 9 February 2023 for representatives of Chagossian communities in the UK, Mauritius and the Seychelles to share their views with Lord Goldsmith, then Minister for the Overseas Territories and senior FCDO officials. Two further engagement events took place later that year.

On 3 October 2024, HMG and GoM announced that they had reached a political agreement on the exercise of sovereignty over the Chagos Archipelago, including Diego Garcia. HMG would continue to exercise rights over Diego Garcia, for an initial period of 99 years to allow the continued operation of the defence facility there. The political agreement was subject to finalisation in the Treaty between the UK and Mauritius. A Joint Statement by the Governments announced that:

“Negotiations have been conducted in a constructive and respectful manner, as equal sovereign States, on the basis of international law, and with the intention of resolving all outstanding issues between the United Kingdom and Mauritius concerning the Chagos Archipelago, including those relating to its former inhabitants…

The treaty will address wrongs of the past and demonstrate the commitment of both parties to support the welfare of Chagossians. Mauritius will now be free to implement a programme of resettlement on the islands of the Chagos Archipelago, other than Diego Garcia, and the UK will capitalise a new trust fund, as well as separately provide other support, for the benefit of Chagossians.”

Following this announcement, the Minister of State for the Overseas Territories held a ‘virtual’ meeting with Chagossians, at which Chagossians expressed a range of views.

Another engagement event was held on 11 February 2025 chaired by the Deputy Director with responsibility for BIOT Policy and Sovereignty to provide an update on sovereignty discussions and the UK’s future support for Chagossians.

On 22 May 2025, the Secretary of State together with the Minister for the Overseas Territories met with representatives of different Chagossian groups to update them on Treaty signature and to provide an update on the UK’s support for Chagossians.

The Treaty was concluded on 22 May 2025. It completed the Parliamentary scrutiny process set out under the Constitutional Reform and Governance Act 2010 on 3 July 2025 and a bill to implement the Treaty in domestic law is currently before Parliament. When or if it receives Royal Assent HMG and GoM intend to complete their ratification process. Under the Treaty, HMG and GoM agree that Mauritius is sovereign over the Islands and “in the exercise of its sovereignty” is free to resettle Chagossians on the Islands other than Diego Garcia but is not required to do so. Control of Diego Garcia will continue to be exercised by the UK in its continued operation as a defence facility.

The question before me at this stage of the proceedings is arguability – whether there is an arguable ground for judicial review which has a realistic prospect of success which has been described as a low threshold (see Ramdass v Minister of Finance [2025] UKPC 4 at [5] and Sharma v Brown-Antoine [2006] UKPC 57, [2007]). The leave stage is not designed for lengthy inter partes hearings but to enable a judge to decide whether a case is arguable on a relatively quick consideration of the material available (see R v Inland Revenue Comrs, Ex p National Federation of Self-Employed and Small Businesses Ltd [1982] AC 617 at 644A). In Ramdass the Privy Council considered thatthe significance of the low threshold was

“that a public body seeking to resist the grant of leave for judicial review of its acts or decisions ought generally to be able to demonstrate a knockout blow in a summary way without the need for extensive investigation of and argument on the knockout point relied on.” [59].

An overarching issue between the parties is whether the claims are simply a reworking of previous arguments that have been tried and failed in the courts in the earlier Chagos litigation and a thinly disguised challenge to the UK HMG’s freedom in matters of international treaty making and thus doomed to failure, or, as submitted by the claimants a case simply concerned with accountability for public law failures of importance when a Minister is conducting executive decision-making, that is not concerned with any non-justiciable function of government in foreign relations.

As for the previous litigation concerning the forced displacement of the Chagossians it is worth setting out the points relevant to this case that were decided in the earlier cases. In R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs [2001] QB 1067 (Bancoult No.1) the Divisional Court held that the Immigration Ordinance 1971 purportedly authorising the enforced removal of the population was unlawful since it was ultra vires the BIOT Constitution. But the ruling in Bancoult No. 1 was of no assistance in the next case brought in response to the 2004 Orders, resulting in the Court of Appeal judgment in Chagos Islanders v (1) The Attorney General and (2) Her Majesty’s BIOT Commissioner [2004] EWCA Civ 997 which upheld the judgment of Ouseley J summarily dismissing claims of misfeasance in a public office, unlawful exile and deceit. Ouseley J’s very full and comprehensive judgment after weeks of evidence and submissions was intended to bring “to an end the quest of the displaced inhabitants of the Chagos Islands and their descendants for legal redress against the state directly responsible for expelling them from their homeland.” ([54]). The case was conducted under a Group Litigation Order. Mr Mandarin snr was one of the claimants.

In R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (no. 2) [2008] UKHL 61, (Bancoult No. 2) the House of Lords held by a majority (overturning the Court of Appeal’s judgment [2007] EWCA Civ 498) that the ECHR had not been extended to the BIOT and the Crown’s actions there could not infringe any provisions of the Human Rights Act 1998.

A further complaint to the ECtHR was ruled inadmissible. The court found in its judgment Chagos Islanders v United Kingdom ((2013) 56 EHRR SE15) that “at no time was the right of individual petition extended to BIOT” [62] and “it could not accept the argument that the fact that many of the applicants now live within the United Kingdom brings their complaints within the Court’s competence.” The BIOT cannot be regarded as part of metropolitan United Kingdom since “it is an overseas Crown territory and not part of the United Kingdom itself” [63]. As for the descendants of Chagossians who were not born on the Islands, ECtHR held that they could have no claim to victim status as they had never had a home on the islands [82].

The 2016 resettlement decision referenced at paragraph 17 above was subject to legal challenge. In Bancoult No. 5 both the Divisional Court ([2019] EWHC 221 (Admin)) and the Court of Appeal dismissed the claims for judicial review of the defendant’s resettlement decision and the decision to continue to prohibit the Chagossians’ claimed right of abode on the Islands. A chronology and background facts are helpfully set out in paragraphs [3]- [70] of the Court of Appeal judgment. In Bancoult No. 5, between the Divisional Court Judgment and the Court of Appeal hearing, at the request of the General Assembly of the United Nations, the International Court of Justice (“ICJ”) issued an advisory opinion that the decolonisation of Mauritius had not been lawfully completed when Mauritius gained independence in 1968 and that the resettlement from the Chagos Islands of Chagossians with Mauritian nationality, related to the protection of their human rights, and was a matter for the General Assembly to resolve during the decolonisation process. A resolution of the General Assembly, in May 2019, demanded that the UK withdraw its administration from the Islands within six months, in order to allow Mauritius to complete its decolonisation, and urged the UK to cooperate with Mauritian resettlement (including resettlement by Mauritian’s of Chagossian origin). The Court of Appeal held that neither the ICJ’s opinion nor the General Assembly resolution had actually made a decision about the right to resettlement, which had been the claimants’ case under the Convention for the Protection of Human Rights and Fundamental Freedoms in Bancoult No. 5. It would be for the GoM to decide resettlement issues as an internal matter of Mauritian law and any relief sought must be claimed there. Nor did the opinion of the ICJ or the General Assembly resolution engage the Convention and did not enlarge the common law right of abode. There had been no interference with human rights - whether looked at with “anxious scrutiny” or not it made no difference to the outcome of the case - which was that there was no proper basis for interfering with a multifactorial and multi-dimensional decision including matters of political sensitivity, defence and security concerns taken at the highest level. The resettlement decision was both well within the range of permissible decisions and was not irrational, there had been consultation and care and attention had been paid to the responses received in the consultation process.

Turning to the second overarching challenge by the defendant, the principle of justiciability is not in dispute. The general rule (absent any restrictions imposed by primary legislation) is that the power to make or unmake treaties is exercisable without legal authority and that the exercise of that power is not reviewable by the courts (see R (on the application of Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5 and earlier cases). Nor is it in dispute that matters relating to the exercise of the foreign relations prerogative attract an especially broad margin of discretion if they are justiciable at all (see R (on the application of Youssef) v Secretary of State for Foreign and Commonwealth Affairs [2016] UKSC 3 at [24] and R (Al Rawi) v Secretary of State for Foreign and Commonwealth Affairs [2006] EWCA Civ 1279 at [148].

I cannot accept the argument that the claim is not an attack on the making of a treaty per se, but merely concerned with substantive public law decision-making. The focus of the challenge is on the Treaty and the fact that under the Treaty GoM is not required to allow Chagossians to resettle on the Islands, but merely has GoM a discretion to allow Chagossians to resettle on islands other than Diego Garcia. That appears to be a direct challenge to the foreign affairs prerogative to conclude a treaty on the terms HMG decides and offends the jusiticiability principle. If I am right about that, the defendant has delivered a knockout blow, as per Ramdass.

But if that is not right, the next question is whether the six grounds relied on relate to the exercise of the foreign relations prerogative setting a particularly high hurdle for the grant of relief or if the grounds are properly distinguishable from foreign relations as submitted by Mr Rule.

Here the difficulty for the claimants is that their grounds of review are inextricably intertwined, part and parcel, indivisible from (whichever figure of speech one chooses) from the foreign policy decisions in exactly the same way that was described and identified in the Bancoult cases – the factors and dimensions involved include matters of international political sensitivity, relationships with other countries, such as the United States of America, defence and international security concerns and our international standing, in negotiations concluded at the highest level. An especially broad margin of discretion is to be afforded to the defendant.

The detailed statement of facts and grounds do not state what the subject matter of the consultation should have been, but in the renewal grounds it is said that the consultation should have been carried out on “resettlement, rights of abode and territorial interests”, given the change in circumstances being envisaged - presumably a reference to the Treaty itself - and that the duty arose by fairness and practice.

There is no doubt that the undoubted historical injustice done to the Chagossians is a powerful background to this case, but the brutal reality is that the Chagossians have never had any right of abode or settlement on the Islands since their ancestors were first brought there. It is unclear what “territorial interests” means, and it was not developed in the course of argument. It is hard to see therefore what the change in circumstances is from the Chagossians’ lack of right of abode before and after the Treaty and this claim is no more than a further attempt to re-run the arguments that were dismissed in Bancoult No. 2 and the House of Lords which refused to strike down the terms of the 2004 Order.

But ignoring that difficulty for a moment, there are a number of other arguments advanced by the defendant both of which are fatal to this ground of challenge. Firstly, issues of resettlement, right of abode and territorial interests in the Islands (which, vague as it is, would appear from the pre-action correspondence and statement of case to include issues of sovereignty) fall squarely within foreign policy considerations and the subject matter of the Treaty.

Secondly, the premise that the duty to consult arose is flimsy. The ministerial statements do not amount to a legitimate expectation of a promise to consult, but were the expression of an intention to “engage” – not the required clear and unambiguous promise to consult devoid of relevant qualification (see Secretary of State for Work and Pensions v Everleigh [2023] EWCA Civ 810 at [81]). Nor does the historical injustice done to the Chagossians nearly 60 years ago result in an exceptional common law duty of fairness to consult now on a Treaty that does not alter the current position of there being no right of abode for Chagossians on the Islands. Put bluntly, the Treaty does not deprive the claimants of any rights that they currently enjoy.

As to the argument that the past engagement and consultation with Chagossians and others in 2009 prior to the MPA and in 2015/16 amounts to the establishment of a practice, the difficulty is that the subject matter of the earlier consultations, even if Gunning compliant, were not about sovereignty. It cannot be concluded that earlier consultation processes establish a settled practice requiring consultation about sovereignty.

It is not arguable that there was any obligation to consult prior to the signing of the Treaty.

The claimants seek to argue that the circumstances have changed since the earlier litigation in which rationality challenges were rejected by the courts. It is argued that the defendant can no longer rely on national security, defence, cost and feasibility to deny resettlement on the Islands, other than Diego Garcia, since those arguments have fallen away on the decision to allow transfer of sovereignty to Mauritius. In the context of the history of the treatment of the Chagossians by the UK and also Mauritius it is argued that Chagossians should have been allowed the right of abode to the outer islands (i.e. all the Islands other than Diego Garcia) before any transfer of sovereignty to Mauritius which is an important matter that the defendant has failed to consider. Six other matters are relied on that the defendant has irrationally failed to consider: that there be formal and open recognition that the Chagossians are a defined racial group; the existing visitation rights of Chagossians to their ancestral lands should have been preserved; the democratic or general wishes of the Chagossians have not been respected; the historical and cultural significance of the Islands to the Chagossian community has been ignored; all to be seen in the exceptional context of the shameful past treatment of Chagossians.

It is not necessary to engage with the detail of the specific ground relied on – it is a complete answer to this head of challenge that the decision of HMG to transfer sovereignty to the Islands is a high policy question not amenable to judicial review – see e.g. Miller, Council of Civil Service Unions v Minister for the Civil Service [1985] 1 AC 374 p.398 and Rahmatullah v Ministry of Defence (No. 2) [2017] UKSC 1 at [15]. In any event, security and defence reasons remain important considerations and arguments challenging the defendant’s decision not to allow resettlement of the outer islands and revert to the 2000-2004 position were conclusively decided against the claimants in Bancoult (No. 5).

But even if the decision is potentially open to legal challenge, such a wide margin of appreciation would be afforded to the defendant as to make this ground unarguable in any event.

The PSED requires that:

“(1)A public authority must, in the exercise of its functions, have due regard to the need to—”

(a)

eliminate discrimination, harassment, victimisation and any other conduct that is prohibited by or under this Act;

(b)

advance equality of opportunity between persons who share a relevant protected characteristic and persons who do not share it;

(c)

foster good relations between persons who share a relevant protected characteristic and persons who do not share it.

(2)

A person who is not a public authority but who exercises public functions must, in the exercise of those functions, have due regard to the matters mentioned in subsection (1).

(3)

Having due regard to the need to advance equality of opportunity between persons who share a relevant protected characteristic and persons who do not share it involves having due regard, in particular, to the need to—

(a)

remove or minimise disadvantages suffered by persons who share a relevant protected characteristic that are connected to that characteristic;

(b)

take steps to meet the needs of persons who share a relevant protected characteristic that are different from the needs of persons who do not share it;

(c)

encourage persons who share a relevant protected characteristic to participate in public life or in any other activity in which participation by such persons is disproportionately low.

(4)

The steps involved in meeting the needs of disabled persons that are different from the needs of persons who are not disabled include, in particular, steps to take account of disabled persons' disabilities.

(5)

Having due regard to the need to foster good relations between persons who share a relevant protected characteristic and persons who do not share it involves having due regard, in particular, to the need to—

(a)

tackle prejudice, and

(b)promote understanding.

(6)

Compliance with the duties in this section may involve treating some persons more favourably than others; but that is not to be taken as permitting conduct that would otherwise be prohibited by or under this Act.

(7)

The relevant protected characteristics are—

age;

disability;

gender reassignment;

pregnancy and maternity;

race;

religion or belief;

sex;

sexual orientation.”

This ground of review claimed that there had been an absence of “due regard” in the discharge of the PSED. The defendant accepted for the purposes of the litigation that the Chagossians are a race within the meaning of s. 149(7) Equality Act 2010. A number of points were raised by both sides – such as whether there had been substantive compliance with the duty; whether an Equality Impact Assessment dated 11 March 2025 disclosed in the run up to the hearing by the defendant was an ex post facto document; and, the extent to which R (Marouf) v Secretary of State for Foreign Commonwealth and Development Affairs [2023] UKSC 23 disapproved the Divisional Court judgment in Bancoult No. 5 about the territorial scope of the PSED – but none of those are necessary to consider in any detail since s.149 does not apply to a decision that will be given effect by primary legislation (see R (on the application of Adiatu) v HM Treasury [2020] EWHC 1554 (Admin) [229]- [238]. It is to be remembered that following its signing by HMG and GoM, the Treaty is currently in a Bill before parliament. It is well established that the courts cannot question the legitimacy of an Act of Parliament and the “functions” of a public authority referred to in s.149 do not include the preparation and promotion of an Act of Parliament. The matter is left beyond any doubt by para 14, schedule 18 to the Equality Act 2010 which expressly excludes decisions relating to primary legislation from the scope of s.149. The analysis does not change, just because the Bill has not yet completed the parliamentary process.

It therefore follows that the PSED does not apply and this ground too is unarguable.

These grounds can be conveniently taken together. The claimants accept the fact that in the previous litigation the courts have consistently found that the Human Rights Act 1988 and the Convention obligations do not extend to the BIOT. But they submit that separate territorial jurisdiction is not needed since they are UK citizens affected by HMG decisions: as British citizens they have rights to private and family life under art.8 and they have protection from discrimination as Chagossians: they are either entitled to be considered a racial group in their own right or have “other status” protection as Chagossians for the purposes of art.14. They are affected by the defendant’s decisions in the UK about sovereignty of the Chagos Islands which affects them as UK citizens. Further or alternatively they rely on Thlimmenos v Greece (2000) 32 EHRR 12 and argue that the defendant is obliged to treat British citizens of Chagossian origin from those who do not have Chagossian heritage differently, since their situation is significantly different and they alone are adversely affected to others who were not forcibly expelled from their homeland in the mid 20^th century.

Art.14 is a parasitic right and ground 4 is thus, on the face of it, incapable of being a stand alone complaint. The claimants’ argument that the defendants decisions bring them within the ambit of substantive rights, but it is not properly explained why. As for art.8 – either as a stand alone complaint, or in conjunction with art.14 – it is also very problematic. The difficulty is the Chagossians’ lack of any rights of abode in the Islands – this is not a case of rights being taken away but of their never having had them. I appreciate the circularity of the argument, and the claimants’ perception that an original injustice has been compounded, but the claimants’ grounds do not give rise to an arguable claim.

The claimants argue that in the exceptional and unique circumstances of the case and their historic shameful treatment a duty to act fairly towards the Chagossians arose and required a survey or referendum of the Chagossian people as to their wishes in relation to (a) sovereignty and/or (b) the granting of a right of abode or resettlement or other rights presently deprived by domestic legislative provision; (c) recognition as a racial group; (d) practical and legal steps to continue their ability to visit the Islands for cultural purposes and financial assistance to do so, as a matter of procedural fairness. There was considerable overlap with ground 2.

Mr Rule was unable to point to a common law right to support his argument but relied on the uniqueness of the context and the history. There are a number of difficulties for the claimants with this ground of review, which to some extent overlap with the difficulties faced in other grounds, but are necessary to repeat briefly here. Since issues of sovereignty are not justiciable there is no peg on which the claimants can hang an argument for a procedurally fair decision-making process, but in any event the engagement exercises conducted by the defendant were considered by him to provide sufficient information about the Chagossians’ range of views. Mr Rule relies on R (Howard League for Penal Reform) v Lord Chancellor (ECHR intervening) [2017] 4 WLR 92 (CA) for the proposition that procedural fairness obligations can arise in contexts where no tortious claim or Convention right lies. But in that, and similar cases, there was something that was being taken away – changes to legal aid eligibility in the Howard League case. Here the Chagossians did not have a right of abode or settlement in the Islands. In any event the issue was determined in Bancoult No. 5 and cannot now be reopened. This ground too is unarguable.

A further argument developed both on the papers and during the course of argument was that the benefit of allowing the claim to proceed to a full hearing would enable full disclosure of relevant documents which could support the claimants’ case and given the interest of the public and the international interest in the issue of the sovereignty of the Chagos Islands it would be in the public interest for there to be a fully argued hearing.

I do not accept the argument. There is sufficient evidence and documentation for the Court to have confidence that the case is not arguable and that there would be no benefit from a substantive hearing which would be bound to fail.

The passing decades since the expulsion of the Chagossians from the Islands time have not healed the claimants’ sense of injustice. Their desire to return to their homeland has not abated. On an initial reading of the papers the strength of the defendant’s arguments shone through, but I reserved judgment for a number of reasons. Partly because of the wide-ranging nature of the allegations, the volume of paperwork and the long list of essential reading provided combined with insufficient pre-reading time. Also, in deference to the strength of the claimants’ feelings and the shamefulness of the treatment of the Chagossian people in the 1960s and 70s. I also had other cases in my list that day. Unfortunately, health issues and pressure of other work prevented me from preparing my judgment sooner for which I once again apologise. I appreciate that a quick decision is intended at or soon after an oral renewal hearing. Having now had time to read more deeply into the case papers, the claimants’ arguments remain as they first appeared for the reasons set out above. The defendant has delivered “a clear knock out blow” to each element of the claims, permission is refused and the claims are dismissed. It is therefore not necessary to consider the claimants’ application for a costs capping order.