Who could replace Peter Mandelson as US ambassador? | Politics News

Sir Keir Starmer is scrambling to find a new US ambassador after sacking Lord Peter Mandelson over fresh revelations about his friendship with paedophile Jeffry Epstein.

The prime minister will want to act fast, given Donald Trump is due to make an unprecedented second state visit to the UK next week.

The ambassador serves as the primary channel of communication between the two nations, representing Britain’s interests in the US.

It has typically gone to a career diplomat – though in Mandelson’s case it went to a political player. Here’s who could replace him.

James Roscoe

James Roscoe has taken over from Mandelson as interim ambassador. While there is no suggestion yet that he could stay in the role permanently, he has an impressive CV in this line of work.

Roscoe has served as the deputy head of mission at the British Embassy in Washington since July 2022 – essentially the ambassador’s second-in-command – and before that was the UK ambassador to the UN General Assembly from 2019.

David Miliband

David Miliband, the brother of energy secretary Ed Miliband, quit frontline politics after losing the Labour leadership race to his sibling in 2010.

The former foreign secretary has been living in the US for the past decade, where he oversees the International Rescue Committee’s aid operations. However there has long been speculation he could return to his old line of work and he was reported to be on the shortlist when Mandelson got the job last year.

George Osborne

Another political appointment Sir Keir Starmer could make, though perhaps a less obvious choice, is the former Conservative chancellor George Osborne.

As the architect of the Tories’ austerity agenda, he is disliked by many within the Labour Party. However, he has had a friendship with JD Vance going back years and reportedly helped arrange the vice president’s holiday to the Cotswolds this summer – earning him the nickname “schmoozer in chief”.

According to Sir Keir’s biographer Tom Baldwin, senior Number 10 aides had pushed for him to get the ambassador role last year. However, such an appointment might upset backbench MPs at a time when the prime minister is seeking to build bridges.

Sir Richard Moore

Another name being tipped for the job is Sir Richard Moore, the outgoing chief of MI6 who is due to step down this autumn. The spymaster has spent the past four years heading the secret intelligence service and is said to be regarded by diplomats as a “safe pair of hands” – something that might be tempting for Sir Keir after his appointment of Mandelson backfired.

Former Tory defence secretary Ben Wallace said Sir Richard would be his choice – though he also added that Mr Miliband “would be a good fit for Labour” if the prime minister wants another political appointee.

Karen Pierce

Karen Pierce served as the US ambassador between March 2020 and January 2025, during both Donald Trump’s first term in office and Joe Biden’s presidency.

She is highly regarded in Washington and was praised by Sir Keir’s government during her transition period before Mandelson took over, with cabinet minister Pat McFadden telling Sky News she was doing an “excellent job”.

However, as our international affairs editor Dominic Waghorn points out, reappointing her would be an admission the prime minister made a mistake appointing Mandelson instead of keeping her on, say diplomatic observers.

Baroness Catherine Ashton

Baroness Catherine Ashton is another possible contender. The Labour peer served as a junior minister in Tony Blair’s government and has a distinguished career as a diplomat. She took over from Mandelson as EU trade commissioner in 2008 and then served as the first vice president of the European Commission and high representative of the EU for foreign affairs and security policy from 2009-2014.