January 23, 2025

Donald Trump is reportedly still threatening to block Peter Mandelson’s appointment as Britain’s next ambassador to Washington, unless the UK government agrees to impose tight restrictions on his conduct.

The incoming Trump administration is said to be pressuring Sir Keir Starmer to bow to these “undiplomatic” demands or risk an unprecedented refusal of his chosen envoy. A source close to the Trump team claimed the president remains determined to reject Lord Mandelson’s credentials but might grant them “conditionally” with “a very short leash”.

It was revealed over the weekend that Mr Trump was mulling the rarely used tactic of rejecting an ambassador’s credentials. No British ambassador to the US, nor American ambassador to the UK, is believed to have been turned away in this fashion.

Much of the disquiet reportedly stems from Lord Mandelson’s perceived favourability towards strong ties with China. The Labour government’s outreach to Beijing – including Chancellor Rachel Reeves’s recent high-profile trip – has raised eyebrows in Washington. A White House source claimed: “It seems the Starmer government is flirting with China as a fallback for a relationship with the US. Nobody here is buying it; it’s completely ridiculous and undermines the British government’s position.”

Downing Street officials have denied claims of a rift among Sir Keir’s senior advisers over Lord Mandelson’s appointment. Although chief of staff Morgan McSweeney has been mentioned as a supporter, while national security adviser Jonathan Powell is rumoured to have reservations, a senior official insisted any such suggestion was “absolutely not” accurate.

Nevertheless, the UK embassy in Washington appears alive to the concerns surrounding the ex-European commissioner and cabinet minister. Dame Karen Pierce, the current ambassador, made an unexpected appearance at a Friday inauguration event hosted by right-wing UK and US figures. She reportedly asked several guests for their views on Lord Mandelson’s proposed arrival.

Dame Karen’s presence also sparked speculation that it was intended to prevent Lord Mandelson from attending. Current and incoming ambassadors cannot appear at the same event under protocol rules, and the party was ostensibly intended to introduce Lord Mandelson to members of Mr Trump’s inner circle.

The Trump administration is well aware that a refusal to accept Lord Mandelson would deliver “a humiliation” for Sir Keir, who was not invited to the inauguration – a significant snub given that other foreign leaders did receive invitations.

Tensions between the Starmer government and the incoming White House team date back to the UK Labour Party’s decision to send over 100 activists to support Kamala Harris, Mr Trump’s Democratic rival, during the presidential campaign. Adding to the strain, tech entrepreneur Elon Musk, an ally of Mr Trump, has used his social media platforms to criticise Sir Keir over issues ranging from far-right riots in Britain to the jailing of activist Tommy Robinson, with accusations that Labour is “anti-free speech”.

In parallel, senior Republicans are pushing for Mr Trump to explicitly back Nigel Farage and his Reform UK party in the next UK general election.

Downing Street has dismissed reports of a looming credibility crisis, calling talk of Lord Mandelson’s possible rejection by Washington “speculation”. However, the risk of a diplomatic impasse remains, with Washington insiders insisting the Starmer administration will need to address concerns over the potential envoy’s track record — particularly regarding China — if it is to avoid an unprecedented veto by President Trump.

Read more:
Trump poised to reject Mandelson as UK ambassador to the US