Sir Keir Starmer’s plan to hand over the Chagos Islands to Mauritius is a “betrayal of the British people”, Priti Patel has claimed. The shadow foreign secretary called on the prime minister to stop discussions over the Indian Ocean archipelago “full stop”. And she called on Sir Keir to “go back to base camp” and re-examine a non-binding ruling from the International Court of Justice (ICJ) that Britain was illegally occupying the islands, home to the vital Diego Garcia military base.

Amid speculation a new version of the deal, which followed a change of government in Mauritius, could double the overall cost of the agreement, Ms Patel said it is “simply not right” to commit up to £18 billion at a time when pensioners have had their winter fuel payments scrapped and farmers are being hit with an inheritance tax raid. “Quite frankly, we should stop this discussion full stop,” Ms Patel told BBC Radio 4’s Today programme.

She added: “It absolutely looks like a betrayal of the British people, a betrayal of our territory.”. Ms Patel said: “We should go back to base camp, look at the judgment and say there are other ways of doing this without just handing over a sovereign territory, and certainly without committing anything from £9 billion to £18 billion at a time when we constantly hear from the government there is a financial crisis here.”.

Ms Patel’s intervention came after reports the UK could end up paying £18 billion instead of the original £9 billion under the original agreement to lease back Diego Garcia for 99 years. Unlike the original deal, which new Mauritian PM Navin Ramgoolam said was “not good enough”, there would also be no automatic extension mechanism after 99 years. Her colleague, shadow justice secretary Robert Jenrick, went further, describing Sir Keir as a “quisling”, a term for someone who collaborates with an occupying force in their own country. Mr Jenrick and Ms Patel were condemned for their comments by Brendan Cox, the husband of the murdered MP Jo Cox, who said: “Calling fellow MPs ‘quislings’ & ‘traitors’ isn’t just a pathetic, and painfully inauthentic, attempt to sound populist - it’s also dangerous.

“MPs know they are all at risk from violence, threats & even murder - yet Jenrick uses language that he knows will increase that threat.”. And her comments came amid growing opposition to the deal in Sir Keir’s cabinet, with the PM’s top team reportedly increasingly concerned about the optics of handing huge sums to Mauritius to give up control of the islands while Britain’s public finances are squeezed.

A foreign office spokesman said the £18 billion figure was “inaccurate and misleading”, but declined to provide an alternative figure. And, despite numerous pledges to publish the cost of the deal by ministers in the Commons, officials would not commit to going ahead with that pledge. The reports followed an answer in the Mauritian parliament by Mr Ramgoolam where he stated that an agreement would be signed between the UK and Mauritius regarding Chagos.

However, he added that the British are still waiting for the approval of the Trump administration. And, in a blow to Sir Keir’s hopes of passing the agreement in the coming weeks, a White House spokesperson told The Independent that President Trump has not given it his blessing. There are serious concerns about the top secret joint US/UK airbase on Diego Garcia and the potential for Chinese interference if the UK gives up sovereignty on the islands.

And while the Biden administration had been happy to support the old deal struck last year to hand over the islands, Trump has been taking advice from Brexiteers and right-wingers in the UK to veto the agreement. A White House official said: “The Trump administration continues to review the British government’s agreement with Mauritius and potential implications for Naval Support Facility Diego Garcia.”.

It is understood that new secretary of state Marco Rubio and the UK foreign secretary David Lammy are due to meet about the issue at a conference in Munich next week. In their first conversation, Mr Rubio made it clear that he was concerned about Chinese interference on the islands. The subject could also come up when Sir Keir meets Mr Trump in the coming weeks. Speaking for the government on Wednesday morning, Steve Reed said the deal on the table “secures the future of that military base”.