An Open Letter to the Prime Minister of the United Kingdom on Folhlhavai (Chagos Archipelago) and the Unanswered Question of Antecedent Title

The Rt Hon Andy Burnham MP
Prime Minister of the United Kingdom
10 Downing Street
London

20 September 2026

Dear Prime Minister,

World leaders are gathering in New York ahead of the High-Level Week of the eighty-first session of the United Nations General Assembly. The General Debate opens in two days. We write to you about an unresolved question. Pen for Rights has received two substantive responses on this question from the Foreign, Commonwealth and Development Office over the past year. The first, TO2025/31423 of 11 November 2025, replied to our correspondence of 27 August 2025. The second, TO2025/41822 of 26 August 2026, replied to our further correspondence of 22 December 2025 and 29 June 2026. The question concerns the islands historically known to Maldivians as Folhlhavai. It reaches behind the 1965 detachment of the islands from colonial Mauritius, behind British administration itself, to the territorial history of the central Indian Ocean before European colonial rule imposed its own geography upon the region. We are grateful that the Government responded at length. We take Britain’s replies on their own terms, because they contain more than Britain may have intended.

TO2025/31423 states that “the Maldives and Mauritius were never part of the same colony under British rule.” It further states that the two territories “were administered separately and never grouped under a single colonial administration.” We do not offer that statement as our characterisation of the historical record. It is Britain’s own.

Britain’s own case before the International Court of Justice adds an important fact. In oral submissions on 3 September 2018, counsel for the United Kingdom told the Court that “the Chagos Islands have no geographical connection with Mauritius.” Counsel placed the distance between the archipelago and Mauritius at approximately 2,150 kilometres. Counsel then explained that the islands had been administered as a dependency of Mauritius “for reasons of administrative convenience.” Counsel described that arrangement as following French practice before 1810.

Those statements raise a question that neither FCDO response confronts. Britain distinguishes the colonial histories of the Maldives and Mauritius. Britain also describes the connection between Folhlhavai and Mauritius as one of administrative convenience despite the absence of geographical connection. On what basis can that colonial administrative arrangement now be treated as determining an asserted Maldivian title said to arise before the arrangement itself?

Administrative convenience explains where a colonial power chose to place the machinery of government. It does not by itself establish antecedent territorial title. The continuation of an earlier European colonial arrangement does not establish what territorial relationship existed before European administration began.

Nothing that follows in either FCDO letter answers that question. The 2019 Advisory Opinion of the International Court of Justice concerned the legal consequences of the separation of the Chagos Archipelago from Mauritius in 1965. The Court concluded that the decolonisation of Mauritius had not been lawfully completed in 1968. The 2021 proceedings before the Special Chamber of the International Tribunal for the Law of the Sea concerned maritime delimitation between Mauritius and the Maldives. The antecedent territorial title now asserted on behalf of the Maldives was not the question determined in either proceeding.

Nor did parliamentary scrutiny of the UK-Mauritius Agreement supply what the judicial proceedings did not. TO2025/31423 records that the Agreement was laid before Parliament under the Constitutional Reform and Governance Act 2010. It records that the statutory scrutiny period ended. It records that neither House objected to the Government proceeding to ratification. That parliamentary process cannot be converted into an adjudication of antecedent territorial title. Non-objection to the ratification of a treaty is not a judicial determination of a third State’s historical claim. That is particularly true where the claim was not the question before Parliament.

The same letter tells us that the Agreement “has been backed by key allies and international partners.” Those partners are the United States, Australia, New Zealand and Canada among Britain’s Five Eyes allies, and India, Japan and South Korea besides. These are significant States. Their support may bear on the diplomatic and security merits of the settlement. It cannot determine the historical question. Seven governments endorsing an arrangement does not constitute seven governments examining a claim to antecedent territorial title. Still less does it constitute seven governments resolving that claim.

TO2025/41822 adds a further dimension. Responding to the CERD decision of 2 December 2025, Britain states that it does not agree with the Committee’s approach. Britain maintains that the Chagos Archipelago has no permanent population and has never been self-governing. On that basis, Britain says no question of self-determination for its population arises. Britain says the relevant right was that of Mauritius rather than of the Chagossians. The same letter rejects any legal basis for a Chagossian “government in exile.” It also acknowledges, in the Government’s own words, its regret for “the manner in which Chagossians were removed from the islands in the 60’s and 70’s.” It recognises “the importance of the islands… to Chagossians.” We do not cite these passages to relitigate the Chagossian question, which is not ours to press. We cite them because they complete a pattern.

The difficulty, Prime Minister, is no longer that Britain lacks notice of another history. Britain has been given notice, twice, in writing, under two separate references. Nor can the answer simply be that other governments support the settlement. The question is whether an asserted antecedent territorial claim can be treated as extinguished by an agreement between two States. The State to which that asserted title relates was not a party to that agreement. The asserted title was not adjudicated in the judicial proceedings Britain invokes. Britain’s own Foreign Office acknowledges that the Maldives and Mauritius were never grouped under a single colonial administration.

The timing gives that disagreement particular significance. On 28 September, during the same High-Level Week, the General Assembly will commemorate the twenty-fifth anniversary of the Durban Declaration and Programme of Action. The meeting is expressly concerned with mobilising international support for its full and effective implementation. Britain meanwhile maintains, in TO2025/41822, that it does not agree with the approach taken by CERD in relation to Folhlhavai. That disagreement deserves examination on its legal merits. It also reinforces the need for care before the histories and asserted rights of other Indian Ocean peoples are treated as legally exhausted by arrangements in which they did not participate.

There is a broader principle at stake. Mauritius’s own decolonisation case demonstrates why it matters. The international process concerning Mauritius did not simply accept the colonial arrangements surrounding the 1965 separation as determinative of lawful decolonisation. The ICJ examined the circumstances in which that separation occurred. It concluded that the decolonisation of Mauritius had not been lawfully completed in 1968.

We ask that the historical inquiry not end arbitrarily. It should be permitted to travel further back. It should reach beyond 1965. It should also reach beyond the administrative boundaries drawn by European colonial government. The inquiry should not stop at whichever colonial layer is convenient to the present settlement. A process is not decolonisation if it is willing to interrogate one imperial arrangement and declare the next one beneath it beyond question.

We are not asking Britain to recognise Maldivian sovereignty over Folhlhavai. We are not asking Britain to prejudge a claim that has not received international examination. Nor are we asking Britain to determine the position of the Chagossian community. Views within that community differ. Their position is not ours to adjudicate.

We ask for something more modest. For that reason, it should be harder to decline. Britain should distinguish between implementing a bilateral treaty and treating that implementation as though it had judicially extinguished a third State’s unadjudicated historical claim. Those are different propositions. The second does not follow from the first merely because it would be convenient if it did.

We accordingly ask the Government to address the following, specifically and in writing.

1. Identify the adjudication. Identify any judgment, advisory opinion, award or other international judicial determination in which the antecedent territorial title of the Maldives to Folhlhavai, prior to European colonial administration, was pleaded, examined and determined.

2. Clarify Britain’s position. Confirm whether the United Kingdom considers the 2019 ICJ Advisory Opinion, the 2021 ITLOS Special Chamber judgment, or parliamentary scrutiny of the UK-Mauritius Agreement under CRAG 2010 to have determined that antecedent question. If so, identify the passages or materials on which the Government relies.

3. Explain the consequence of Britain’s own historical position. Explain how the Foreign, Commonwealth and Development Office’s acknowledgement that the Maldives and Mauritius “were administered separately and never grouped under a single colonial administration” has been taken into account in concluding that sovereignty over Folhlhavai is exclusively a bilateral matter between the United Kingdom and Mauritius.

4. Preserve the question rather than prejudge it. Pending proper examination of the antecedent claim, acknowledge that implementation of the UK-Mauritius arrangements should not itself be represented as a judicial determination extinguishing any antecedent territorial rights that may ultimately be established on behalf of the Maldives under international law.

Prime Minister, Britain did not create the entire history that produced this dispute. It became one of its principal authors during the colonial period. It remains an actor in its proposed resolution today. Britain has no obligation to accept an unproven Maldivian claim. It should equally have no basis for treating that claim as extinguished without adjudication. The four questions above therefore ask for neither recognition nor concession. They ask Britain to identify where the antecedent question was actually determined or, if it was not, to acknowledge that elementary fact.

A claim cannot have been judicially rejected if it has never been judicially heard. At UNGA 81, when decolonisation, equality and the international rule of law are again before the world, acknowledging that distinction would be a modest act. It would also be an important one.

Respectfully,

Pen for Rights – Republic of Maldives
Indian Ocean Decolonisation Initiative