LONDON, May 23 – Britain on Thursday signed a landmark agreement with Mauritius to cede sovereignty over the Chagos Islands, paving the way for the long-term operation of the strategically vital U.S.-UK military base on Diego Garcia under a 99-year lease.
The multibillion-pound deal was finalized after a UK court lifted a last-minute injunction that temporarily halted the signing ceremony. Prime Minister Keir Starmer said the agreement would safeguard national security and reinforce the UK’s ability to respond to global threats.
“The strategic location of this base is of the utmost significance to Britain, from deploying aircraft to defeat terrorists in Iraq and Afghanistan to anticipating threats in the Red Sea and Indo-Pacific,” Starmer told reporters. “By agreeing to this deal now, on our terms, we’re securing strong protections.”
The financial terms include a £3 billion payment to Mauritius over the life of the agreement, with an option to extend for 50 years and Britain retaining a right of first refusal thereafter.
The deal ends decades of legal and diplomatic wrangling over the archipelago, which was separated from Mauritius by Britain in the 1960s. Mauritius Prime Minister Navin Ramgoolam hailed the agreement as a final step in the decolonization process.
“It’s total recognition of our sovereignty on the Chagos, including Diego Garcia,” Ramgoolam said in a televised address in Creole.
U.S. Secretary of State Marco Rubio welcomed the agreement, saying it “secures the long-term, stable, and effective operation” of the Diego Garcia facility, which has been used in recent operations in Yemen, Gaza, and Afghanistan.
The signing faced a last-minute hurdle after Bertrice Pompe, a British citizen born in Diego Garcia, won an interim injunction in the early hours of Thursday. Judge Martin Chamberlain lifted the injunction later in the day, ruling that British interests would be “substantially prejudiced” by further delay.
Government lawyers argued that any hold-up threatened Britain’s international relations, including with the United States.
The agreement has stirred criticism from opposition politicians. Conservative foreign affairs spokesperson Priti Patel called it a “Chagos Surrender Deal,” warning that ceding sovereignty could deepen China’s influence in the Indian Ocean through Mauritius.
The deal also drew fire from members of the Chagossian diaspora, many of whom were forcibly removed from the islands over 50 years ago and now reside in Britain. Pompe and others have criticized the agreement for excluding Chagossians from the negotiation process.
Despite political backlash, the Starmer government views the agreement as a diplomatic win amid domestic scrutiny over recent welfare cuts and economic challenges.
