The Republican’s astonishing US election victory poses a huge problem for the Prime Minister.

Despite Sir Keir’s vow that the UK-US special relationship will “continue to prosper” following Trump’s “historic election victory” he knows there is work to do.

Sir Keir will be keen to build bridges with the President-elect after the Trump campaign filed a legal complaint about Labour activists supporting Kamala Harris.

Trump returning to the White House could cause diplomatic headaches for the UK, with potential splits on trade policy and US support for Ukraine and NATO.

Foreign Secretary David Lammy said he is looking forward to working with Trump and his running mate JD Vance.

Mr Lammy has spent time seeking to form a close relationship with the Trump campaign, despite a history of outspoken criticism of his record – including calling him a “racist and KKK/neo-Nazi sympathiser” in 2017 and a “tyrant in a toupee” a year later.

This morning he said the UK has “no greater friend than the US, with the special relationship being cherished on both sides of the Atlantic for more than 80 years.”

Trump’s power at the start of his second presidency could be untrammelled, with the Republicans also appearing on course to win a Senate majority and retaining control in the House of Representatives.

He has long complained about US tax dollars funding European security and has been highly critical about Nato members not spending enough.

Trump has also repeatedly claimed he would bring the war in Ukraine to an end, although he has not set out how he would achieve this.

And then there’s the Elon Musk factor.

Sir Keir was embroiled in a very public spat with the world’s richest person and Trump’s biggest supporter as riots swept Britain in the summer.

That doesn’t look like a good move now considering the Billionaire’s social media influence with X/Twitter.

ReformUK leader Nigel Farage summed up the colossal double-whammy of Trump-Musk telling the BBC: “What you are going to see from this Trump administration, and I’m guessing that Elon Musk will be the man that is tasked to do it, is there will be a big fightback against the administrative bureaucratic state which is far too big, far too powerful and actually very undemocratic.”