Nigel Farage hit out at the “terrible” Chagos Islands deal after Donald Trump signed off the plans. Downing Street said the agreement to hand the British Indian Ocean Territory to Mauritius is being “finalised” after winning approval from the US.

The controversial plan will see the UK give up sovereignty of the Chagos Islands but pay to lease back the strategically important Diego Garcia military base, which is used by the US. Reform UK leader Mr Farage, who is a close ally of Mr Trump, said on X: “The Chagos Islands surrender means we will pay Mauritius £90m a year for 99 years.

“If inflation averages at 3%, it will cost us over £50billion. This is a terrible deal for British taxpayers.”

Discussions are ongoing between the UK and the Mauritian government over the terms of the deal.

The Prime Minister’s official spokesman said today: “The finalisation of the deal is ongoing.”

US President Mr Trump indicated his backing for the deal during Sir Keir Starmer‘s visit to Washington in February, saying: “I have a feeling it’s going to work out very well”.

The Prime Minister’s official spokesman said: “You will have seen from the President that he recognised the strength of the deal.

“I think we are now working with the Mauritian government to finalise the deal and sign the treaty.

“My understanding is it’s now between us and the Mauritian government to finalise the deal, following the discussions with the US.”

A deal was initially announced last year, but a change of administration in Mauritius and the return of Mr Trump to the White House put it in doubt.

The Government has argued that it has to give up sovereignty over the territory due to international legal rulings in favour of Mauritius.

Reports have suggested the deal could cost £90 million a year to secure the use of Diego Garcia, with payments front-loaded to win the support of the Mauritian government.