The UK Government has agreed to hand sovereignty of the Chagos Islands to Mauritius in return for retaining control of the military base on Diego Garcia.
Under the deal, Britain has secured the right to operate the base, which is on the largest island in the archipelago, for at least the next 99 years.
In the early 1970s, the UK evicted almost 2,000 Chagossians to make way for an airbase, which the UK leases to the US.
Britain agreed to begin negotiations with Mauritius in 2022 over the future of the islands, backing down from its long-standing resistance to doing so after international pressure.
Britain detached the Chagos Islands from Mauritius when it granted independence in 1965 to create the British Indian Ocean Territory (BIOT).
Mauritius maintains the islands are its own and Chagossians have fought for their return in the British courts.
The UK’s Foreign Office says Mauritius will assume sovereignty over BIOT with the UK authorised to exercise the sovereign rights of Mauritius on Diego Garcia.
Foreign Secretary David Lammy said the agreement “secures this vital military base for the future”.
“This government inherited a situation where the long-term, secure operation of the Diego Garcia military base was under threat, with contested sovereignty and ongoing legal challenges,” he said.
“Today’s agreement secures this vital military base for the future.
“It will strengthen our role in safeguarding global security, shut down any possibility of the Indian Ocean being used as a dangerous illegal migration route to the UK, as well as guaranteeing our long-term relationship with Mauritius, a close Commonwealth partner.”
A Downing Street representative said Prime Minister Keir Starmer spoke to his Mauritian counterpart Pravind Jugnauth this morning.
“The leaders began by welcoming the political agreement achieved today between the UK and Mauritius on the exercise of sovereignty over the Chagos Archipelago after two years of negotiations.
“The Prime Minister reiterated the importance of reaching this deal to protect the continued operation of the UK/US military base on Diego Garcia.
“He underscored his steadfast duty to national and global security which underpinned the political agreement reached today.”
Britain, which has controlled the region since 1814, detached the Chagos Islands in 1965 from Mauritius, a former colony that became independent three years later, to create the British Indian Ocean Territory.
The World Court said in 2019 that Britain should give up control of the islands and said it had wrongfully forced the population to leave in the 1970s to make way for a US airbase.
The United Nations’ highest court, the International Court of Justice in The Hague, has ruled that the UK’s administration of the territory is “unlawful” and must end.
A report from the Policy Exchange think tank last year argued that Britain should not relinquish sovereignty over the islands in return for “an unenforceable promise by a third country that the military base at Diego Garcia will be allowed to continue to operate in the future”.
Richard Ekins, head of Policy Exchange’s Judicial Power Project, called on the British government should halt negotiating a treaty of cession with Mauritius, and should retain Diego Garcia at all costs.
He said the government should recognise that ceding the Chagos Islands “would be an irresponsible act, which would put our strategic interests – and the interests of our closest allies – in danger, while also recklessly undermining fundamental principles of international law.”
