SIR KEIR STARMER’S diplomatic strategy is in disarray after Donald Trump publicly threw him under the bus today over the Chagos Islands deal.

The Prime Minister’s failed appeasement of the US president came under fire after Mr Trump said the plan to hand sovereignty over the islands to Mauritius — while ensuring the US military base there can be retained — was “stupid.”

Liberal Democrat leader Ed Davey said: “This shows Starmer’s approach to Trump has failed. 

“The Chagos deal was sold as proof the government could work with him. Now it’s falling apart. It’s time for the government to stand up to Trump — appeasing a bully never works.”

As part of his offensive against European leaders over their reluctance to acquiesce in his plans to seize Greenland, the US president posted on social media: “Shockingly, our ‘brilliant’ Nato ally, the United Kingdom, is currently planning to give away the Island of Diego Garcia, the site of a vital US military base, to Mauritius, and to do so for no reason whatsoever.

“There is no doubt that China and Russia have noticed this act of total weakness. These are international powers who only recognise strength which is why the United States of America, under my leadership, is now, after only one year, respected like never before.

“The UK giving away extremely important land is an act of great stupidity, and is another in a very long line of national security reasons why Greenland has to be acquired.”

The rebuke, and the sarcastic reference to a “brilliant” ally, are a huge setback for Sir Keir, who has staked all his political reputation on staying the right side of the US president.

Hitherto, the US administration had expressed support for the Chagos deal, to the disappointment of the right in British politics.

The new position reflects the extent to which the Greenland crisis, caused by Mr Trump’s desire to annex the territory, has poisoned relations. 

The president’s change of line was welcomed by Reform boss Nigel Farage, who said “thank goodness Trump has vetoed the surrender of the Chagos islands” and Tory leader Kemi Badenoch also said that she agreed with him.

Despite Mr Trump’s tirade, the government is not likely to reverse the Chagos agreement. 

Downing Street chief secretary Darren Jones said: “The treaty has been signed with the Mauritian government. So I can’t reverse the clock on that. The treaty has been signed.”