The UK must hand over the Chagos Islands to Mauritius, even if Donald Trump scuttles the current proposed agreement, the Mauritian prime minister has said.

Navin Ramgoolam has demanded that, deal or no deal, the Chagos Islands should return to Mauritian control.

“If the deal isn’t signed, we will continue our fight, which began in 1965, to ensure the Chagos archipelago regains Mauritian sovereignty,” he told Defimedia, in a warning to Sir Keir Starmer.

The Chagos Islands have been at the centre of a decades-long sovereignty dispute, with multiple international rulings affirming Mauritius’s claim.

In January 2021, the United Nations’ International Tribunal for the Law of the Sea ruled that Britain had no legal sovereignty over the islands, while the International Court of Justice has ruled that native Chagossians were unlawfully expelled by the UK to make way for a military air base, and that the islands should be handed to Mauritius.

Under the proposed pact, one of Sir Keir’s first major foreign policy decisions, Britain will give the islands to Mauritius, while securing a long-term lease for the air base on Diego Garcia so that Britain and America can still use it.

Diego Garcia has served as a strategic military asset for the UK and the United States and was used as a staging point for operations in Afghanistan and Iraq after the 9/11 terror attacks.

Under the terms of the deal, the lease would cost the UK £9 billion over a decade. Recent reports suggest that Mauritius has been holding out for significantly more.

Last week The Telegraph reported that Donald Trump will rule on the future of the islands after his team directly intervened in the British Government’s deal.

The Telegraph understands that Mr Trump’s team demanded Britain delay its decision to hand back the islands to Mauritius until he was back in the White House.

Mr Trump is expected to review the deal after he retakes office today and is fully briefed on security concerns surrounding Chinese influence over the territory.

Senior members of the Trump team, including Marco Rubio, the incoming secretary of state, and Mike Waltz, White House national security adviser, have said giving away the islands to Mauritius could help China’s military ambitions in the Indo-Pacific.