Chagos Islanders make last-ditch appeal to Donald Trump to veto Labour's 'surrender' deal

The letter is expected to reach the White House this weekend, the Mail reports, just before a crucial parliamentary vote back in Britain on Monday.

Mr Mandarin argues the treaty negotiated by Keir Starmer's National Security Adviser Jonathan Powell endangers a critical military asset in the Indian Ocean.

The First Minister also cautions that the agreement could provide China with "leverage" over the Diego Garcia facility, which serves as a crucial strategic asset.

Under the proposed treaty, Mauritius "would hold sovereignty over every inch of the US base," Mr Mandarin warns.

The White House has previously signalled it would not oppose the deal.

However, opponents believe President Trump has not been fully briefed on the potential dangers to American military operations in the region.

Ministers maintain the agreement is necessary to resolve a long-standing sovereignty dispute and guarantee the base's continued operation.

Mr Mandarin has suggested grateful Chagossians might even name one of the archipelago's 60 islands after the President "to mark the moment America chose strength, fairness and long-term security over a short-term fix".

In his direct appeal, he wrote: "President Trump, you have always been clear... You don't accept deals that tie America's hands. And you don't accept arrangements that look fine on paper but collapse under pressure."

The First Minister argues that halting the treaty would "shut the door on Chinese interference" whilst providing permanent legal certainty for US operations.

He also suggests a pause could enable Chagossians to eventually return to the islands they were forced to leave in the late 1960s.

The Government suffered four defeats in the Lords this week on the legislation required to implement the treaty.

Despite these setbacks, ministers are expected to make another attempt to pass the legislation when Parliament votes on Monday.

The proposed deal would see Britain hand Mauritius payments totalling approximately £30billion in exchange for a 99-year lease on Diego Garcia.

The UK currently holds sovereignty over the island.

Critics argue the arrangement would permanently end any prospect of Chagossian people returning to their homeland - and open the door to Chinese interference over a key British asset.

"I am therefore asking you, Mr President, to do what you do best - call out a bad deal and stop it," Mr Mandarin said.

Labour insists the giveaway is necessary to "ensure access to the base by air and by sea, effectively to patrol the maritime area around the base, and to support the base’s critical national security functions".

Announcing the deal last May, the Prime Minister said that without it, Britain would have been unable to prevent China or any other nation "setting up their own bases on the outer islands or carrying out joint exercises near our base".

But central to the treaty is adhering to an International Court of Justice "Advisory Opinion" which claims that splitting the Chagos Islands off from Mauritius in 1965 was unlawful.

An FCDO spokesman said: “The Diego Garcia military base deal secures the future of the strategically critical UK-US base on Diego Garcia and has been backed by key partners, including the US and all of our 5 EYES allies.

“As the public would rightly expect, we have negotiated robust security provisions to protect the UK and the base for decades to come.

"These provisions have been designed and tested in close cooperation with the highest levels of the US security establishment - the US Administration has publicly and categorically welcomed the deal.

"There is a clear prohibition in the treaty to prevent any other foreign security forces, civilian or military – including the Chinese – from establishing themselves on the outer islands.”