The revelation, exposed on Friday night, forced Labour bosses to withdraw their bill from the House of Lords, ahead of a debate on Monday. Government lawyers will now need to look once more at the bill, and look into the historic legislation that could end up sinking it.

A letter, which was seen by the Daily Telegraph, laid bare the Government’s state of panic over the new set back. It showed the senior ministers admitting that the Chagos deal could not proceed without the US agreeing to completely rewrite its 1966 defence deal with the UK.

It has now become the latest setback in a long line of challenges facing the controversial giveaway of British territory to a foreign government. Last week Mr Trump described the plans as “an act of great stupidity”, in a major blow to Sir Keir.

Now it has been revealed that figures inside the White House are urging Mr Trump to stop the deal dead in its tracks. Officials are said to be calling on the President to refuse to amend the 1966 treaty, which asserts that Britain holds sovereignty over the islands, and must ensure they all remain available to both sides – the UK and the US – for the purposes of defence.

A source told the Telegraph that the White House was unlikely to “accept Mauritius sovereignty” as backlash against the deal rises. Currently the deal would see the UK hand over the archipelago to Mauritius whilst paying a sum thought to be in the billions to ‘lease back’ the Diego Garcia military base.

Kemi Badenoch told the Telegraph that her party had been engaged in “quiet diplomacy” with the Republicans to show how the deal was a “risk to national security”.

She told The Telegraph: “We’ve had so many U-turns – the grooming gangs inquiry, winter fuel payments, family farm tax, digital ID – and now Chagos, which is honestly the biggest one. That’s £35bn we are saving the taxpayer. Let’s be clear, what Labour is trying to do is hand over strategic British territory to Mauritius – a country that is aligned with China.”