Chagos: Three Chagossians Take the British High Court to Contest the Agreement

Three Chagossians have approached the High Court in London to challenge the agreement regarding the return of the Chagos Islands to Mauritius. They accuse the British government of failing to consult their community regarding their rights to residency and self-determination.

On Tuesday, three Chagossian nationals argued before the High Court of Justice in London for permission to file an appeal against the UK Foreign Office. Bertrice Pompe, Misley Mandarin, and Michel Mandarin claim that the government made "illegal decisions or omissions" concerning the Chagos Islands, particularly by not consulting their community on the "right of residency" in this Indian Ocean archipelago.

The hearing, presided over by Judge Stacey, follows a bilateral agreement signed in May 2025 between the UK and Mauritius, which outlines the transfer of sovereignty of the Chagos Islands to the Mauritian state. This pact includes a 99-year lease granted to the UK to maintain its strategic military base on Diego Garcia, the largest of the islands in the archipelago. The agreement, which has yet to be ratified by the British Parliament, was delayed for several hours by an emergency application submitted by Bertrice Pompe, which was ultimately rejected.

Consultations

The plaintiffs, represented by King’s Counsel Philip Rule, criticize the Foreign Office for failing to "adequately and legally consult" the Chagossians regarding their "rights to residency, resettlement, or territorial interests." In his written conclusions, Philip Rule asserts that the ministry committed "illegal decisions or omissions" by not "recognizing, accepting, and addressing the existence of the Chagossian people as an ethnic group," nor allowing "the Chagossian people a right to self-determination." During the hearing, he denounced a "reckless disregard for Chagossian interests" and emphasized an "expectation of consultation" regarding resettlement. The applicants seek to annul the "decisions and actions taken illegally by the defendant in relation to matters affecting the Chagossian people and their interests."

The British government firmly opposes this procedure. Kieron Beal, King’s Counsel representing the Foreign Office, described the appeal as a "collateral attack on an international agreement." He reminded that the Chagos Islands, British Indian Ocean Territory (BIOT), "are not, and have never been, part of the UK." He referenced the tragic history of the archipelago: in 1971, the inhabitants of Diego Garcia were displaced to the outer islands, then "evacuated" to Seychelles or Mauritius. Since then, it has been illegal to enter or reside in the BIOT without a permit. The government has "expressed its sincere regrets" for these expulsions and has repeatedly examined the possibility of resettlement but decided in 2016 not to support or authorize any resettlement program.

Residency

"No Chagossian has ever had a right to residency in the BIOT," Kieron Beal emphasized, adding that this issue now falls "necessarily under the jurisdiction of Mauritius." The measures sought by the plaintiffs, he argues, would compel the government to exercise its "discretionary powers regarding treaty-making and international relations in a manner contrary to all authority and principles."

Judge Stacey will render her decision at a later date. The bill regarding the return of the Chagos archipelago was supported by MPs last week and is set to be reviewed by the House of Lords in November.