Sir Keir Starmer faces “total humiliation” if his plans to hand over the Chagos Islands to Mauritius collapse, MPs have warned.

Tory shadow defence secretary James Cartlidge and Reform leader Nigel Farage have pressed the Government for answers.

Mr Cartlidge said: “If this deal collapses it will be a total humiliation for Starmer and Lammy.”

Mr Farage said: “The Chagos deal is collapsing before our eyes. It was always a bad deal for the UK, the USA and the Chagossian people.”

It follows reports by the BBC earlier this week that new Mauritian prime minister Navin Ramgoolam expressed reservations about the deal that was struck earlier this year, after a meeting with the UK’s national security adviser Jonathan Powell on Monday.

The Government’s position on the Chagos deal “remains unchanged” and the UK is “finalising” the text of the treaty, Number 10 has said, after it was reported that the new Mauritian prime minister has concerns about the agreement.

The Prime Minister’s official spokesman said on Wednesday that final details of the legal text of the treaty are being worked out, with the plan to put them before Parliament for scrutiny next year.

Asked about the reports, the Prime Minister’s official spokesman said: “The UK’s position on this remains unchanged, we have always said that we look forward to engaging with the new Mauritian government and that’s exactly what we’re doing in order to progress the deal.

“We are now finalising the details of legal texts, the treaty, and will be coming forward for parliamentary scrutiny as part of the ratification process next year.”

The UK agreed to hand over the Chagos Islands, also known as the British Indian Ocean Territory, to Mauritius in October.

The Government has said that the agreement has secured the long-term future of a joint US-UK military base on Diego Garcia, the largest of the islands.

However, critics have said it risks allowing China to gain a military foothold in the region.

The agreement over the continued UK-US military presence on Diego Garcia is expected to run for 99 years with an option to renew, with Britain paying an annual sum of money.

David Lammy dismissed criticism of the Chagos Islands deal by the new prime minister in Mauritius and the incoming Trump administration in the US as “politicking” before elections.

Mr Lammy said: “I’m very, very confident that this is a deal that the Mauritians will see, in a cross-party sense, as a good deal for them.”

Donald Trump’s pick for secretary of state, Marco Rubio, warned in October that the agreement posed “a serious threat” to US national security by handing over the islands to a country allied with China.

Mr Lammy said: “This is incredibly sad. I know and I’m sad that there’s been so much politicking about this.

“This process begun under the last (UK) government and there were ministers who understand entirely why this is so important for our national security and global national security.

“The agencies in the United States think this is a good deal. The State Department in the United States thinks this is a good deal and most important of all, the Pentagon and the White House think this is a good deal.

“And that’s not just the principal politicians in those in those areas, it is the system.”