Lord Peter Mandelson’s departure as US Ambassador has left a void in Washington that No10 has yet to permanently fill and sparked speculation over who could be pulled in for the prestigious role.

Following his sacking over historic links to Jeffrey Epstein, No10 announced James Roscoe would be the interim ambassador to the US with immediate effect.

Describing his time in office, Lord Mandelson said that serving as US Ambassador was the “privilege of my life”.

In a letter penned last week, Lord Mandelson thanked staff for their professionalism, saying it was “superb, more so than I have experienced in any public role”.

The letter added: “The circumstances surrounding the announcement today are ones which I deeply regret. I continue to feel utterly awful about my association with Epstein 20 years ago and the plight of his victims.

“I have no alternative to accepting the Prime Minister’s decision and will leave a position in which I have been so incredibly honoured to serve.”

However, just days ago, when asked whether he had sympathy for the former US Ambassador, US President Donald Trump said he “didn’t know him”.

Sir Keir added: “Well, I mean it’s very straightforward.

“Some information came to light last week which wasn’t available when he was appointed and I made a decision about it and that’s very clear.”

Below are six possible candidates to replace Lord Mandelson as the UK’s ambassador to the US.

James Roscoe

James Roscoe, who is currently the interim US Ambassador, could have his tenure made a permanent fixture by the Prime Minister.

Despite not being a household name, Mr Roscoe has significant credentials that could help him land the role.

Mr Roscoe was made deputy head of mission at the British Embassy in Washington in July 2022.

Before that, Mr Roscoe was UK Ambassador to the UN General Assembly from 2019.

From 2016 to 2019, he held the roles of Director for Communication at the Cabinet Office, and subsequently the Department for Exiting the European Union.

Mr Roscoe has also previously served as Communications Secretary to HM The Queen in the Royal Household from 2013 to 2016 and was Chief Press Officer in the Prime Minister’s Office for PMs Blair and Brown from 2006 to 2009.

He has also had postings to: the UK Mission to the UN (2009 to 2012), working on sanctions, counter-terrorism and counter-proliferation issues; to the High Commission in Freetown, Sierra Leone (2004 to 2006); and to the Coalition Provisional Authority in Basra, Iraq (2003 to 2004).

Sir Mark Sedwill

Sir Mark Sedwill is the “frontrunner” in the race to replace Lord Mandelson, according to The Sun’s Political Editor, Harry Cole, despite holding a lucrative role at Rothschild & Co – one of the world’s largest independent financial advisory groups.

Sir Mark’s past roles include being Cabinet Secretary from April 2018 to September 2020 and National Security Advisor from April 2017 to Sept 2020.

Before this, Sir Mark had an illustrious career as the Permanent Secretary at the Home Office (2013-17), FCO Political Director (2012-13), Nato Senior Civilian Representative in Afghanistan (2010-11), HM Ambassador to Afghanistan (2009-10), and Director of UK visas (2006-8).

He first joined the Foreign & Commonwealth Office in 1989, serving in Egypt, Iraq, Cyprus and Pakistan.

Sir Richard Moore

Sir Richard Moore, the soon-to-be-replaced chief of MI6, is another name reported to be in the running to take Lord Mandelson’s position.

Sir Richard was Director General for Political Affairs at the Foreign & Commonwealth Office from April 2018 to August 2020 and served as British Ambassador to Turkey from January 2014 to December 2017.

Previously, he was Director for Europe, Latin America and Globalisation (2010 to 2012) and Director for Programmes and Change (2008 to 2010). He has had postings in Vietnam, Turkey (1990 to 1992), Pakistan and Malaysia.

However, his five-year tenure as head of the UK’s secret intelligence service did not come without its share of trouble.

Back in the summer of 2023, the top civil servant faced tough questions about MI6’s stance on social issues after he added “he/him” pronouns to his Twitter bio.

Sir Richard said: “I can say to you comprehensively that MI6 doesn’t do culture wars.

“But what I do want is for my service to better represent the country we serve.

“That’s a noble aim, in my view, but it’s also an intensely practical aim.

“Diversity brings greater creativity, better problem-solving.”

According to Mr Cole, Sir Richard could be “too woke” for Donald Trump.

Julia Longbottom

Julia Longbottom is the current Ambassador to Japan and has had an extensive career in British diplomatic efforts for nearly 40 years.

After joining the Foreign & Commonwealth Office in 1986, Ms Longbottom has carved out a career in several departments across Europe, the US and Asia.

She was made Minister and Deputy Head of Mission to Japan in 2012 and served in the role for four years. She was then made Ambassador to Japan in March 2021.

Similar to Mr Roscoe, Ms Longbottom is a career diplomat who is widely respected in her current role.

Not to be overlooked is Ms Longbottom’s role during negotiations for Britain to join the CPTPP trading agreement. Such experience would make her a suitable candidate to support further talks with the US on tariffs and trade.

However, it is understood she could be overlooked for the role due to Donald Trump’s aversion to career diplomats.

Barbara Woodward

Ambassador Barbara Woodward is currently the UK’s Permanent Representative to the United Nations in New York.

Since 2020, she has led the UK Mission’s work at the UN to protect and advance UK security and prosperity, and drive progress on global peace and development.

Prior to her role at the UN, Barbara served in the challenging role of the UK Ambassador to the People’s Republic of China.

According to her biography, Ms Woodward took a government-to-government, business-to-business and people-to-people approach to advancing UK interests in China for five years between 2015 and 2020.

During this period, trade between UK and China doubled to $100billion (£74.21billion), suggesting she could be well positioned to boost trade with the US should she be given the role as US Ambassador.

She also oversaw a State Visit by President Xi Jinping to meet Her Late Majesty Queen Elizabeth II at Buckingham Palace.

She was also Deputy Ambassador to China from 2007-2009, including during the 2008 Beijing Olympics and Paralympics.

One particular career highlight came during her tenure at the British Embassy Moscow from 1994-98, where she was awarded an OBE for her role in securing the release of two British hostages from Chechnya.

However, it is understood that her chances are somewhat diminished due to fears she was too soft on China while she served as ambassador.

David Lammy

Understood to be “furious” with Sir Keir’s recent mini-reshuffle, which saw him moved from Foreign Secretary to Justice Secretary and made interim Deputy Prime Minister, his name has emerged as a potential candidate to replace Lord Mandelson, according to Mr Cole.

Having already made ties with Vice President JD Vance during his recent trip to the UK, it appears Mr Lammy has already made inroads in Washington.

Mr Lammy was first elected as Labour MP for Tottenham at the age of 27 in June 2000.

Since then, he has gathered more than a quarter of a century of experience in politics.

He served as a minister in the Labour Government from 2001 to 2010 and was made a Privy Councillor in 2008.

Mr Lammy was in several departments, including the Department of Health and the Department for Constitutional Affairs.

He was also Culture Minister at the Department of Culture, Media and Sport and Higher Education and Intellectual Property Minister at the Department of Business, Innovation and Skills.

However, the now-Justice Secretary has had a chequered history with the US and Mr Trump in particular.

While serving as a backbench MP in 2018, Mr Lammy described Donald Trump as a “tyrant” and “a woman-hating, neo-Nazi-sympathising sociopath”.

Then, ahead of Mr Trump’s first state visit to the UK in 2019, Mr Lammy posted on X that the US President was “deluded, dishonest, xenophobic, narcissistic” and “no friend of Britain”.

Since these comments, he appears to have turned a new leaf, dismissing his previous criticisms as “old news” before insisting he would be able to find “common ground” with Mr Trump.