The appointment ends weeks of indecision by Sir Keir Starmer over whether or not to ship the political heavyweight to have interaction with the incoming administration.
Some inside Britain’s International Workplace had urged the prime minister to stay with US ambassador Dame Karen Pierce, recognized as “the Trump whisperer”.
Nonetheless, Starmer’s allies say he in the end believed the case was overwhelming for sending a veteran politician and massive hitter to Washington, not least given Mandelson’s expertise in commerce points.
“It wasn’t a slam dunk,” stated one individual near the method. “The prime minister took his time. There have been some within the system who needed Karen to hold on. That was an alternative choice.”
Mandelson, a minister beneath Tony Blair and Gordon Brown, is a talented media and political operator, relationship again to his days as Labour’s communications chief within the Eighties when he grew to become recognized as the “Prince of Darkness”.
“He’s an enormous title,” stated one other official near the choice. “He can do Fox Information and the opposite TV channels and that’s an enormous a part of the job. He’s in a league of his personal.”


Mandelson, a former EU commerce commissioner, has additionally been appointed for his commerce experience, with a direct instruction from Starmer to move off the specter of Britain being focused as a part of Trump’s proposed 10-20 per cent tariff on international imports.
“There’s no purpose why Britain ought to be a direct goal,” stated one individual near Starmer. “Peter’s precedence then is to design the type of twenty first century digital and companies financial settlement, however that may be a medium-term goal.”
Earlier talks on a extra formidable free-trade settlement between the 2 nations have damaged down over meals requirements — the UK bans chlorine-washed hen and hormone-treated beef.
Starmer briefly thought of rival candidates earlier within the yr, notably former Labour international secretary David Miliband and former EU international coverage chief Girl Cathy Ashton, however they have been rapidly discarded.
“For a very long time it has been “Peter or not Peter,” stated one Downing Avenue insider. “I by no means heard another title talked about within the ‘or not’ class over latest months. I don’t actually know why it took so lengthy.”
Mandelson is near Starmer however not in his inside circle. The possible ambassador was lower than diplomatic earlier this yr when he instructed Starmer ought to “shed a number of kilos”.
The 71-year-old has additionally been a magnet for controversy through the years. As a minister he was pressured to resign twice from Blair’s authorities and his previous contact with intercourse offender Jeffrey Epstein emerged final yr.
Final month, Mandelson instructed Starmer ought to use Reform UK chief Nigel Farage as a “bridgehead” to construct relations with Trump and Elon Musk. “Did Peter actually say that?” requested one Starmer aide on the time.
His seven-year stint as president of the Nice Britain China Centre, a non-departmental International Workplace physique, has made him a goal for Conservative China hawks and is unlikely to go unnoticed within the Trump group.
Iain Duncan Smith, former Tory chief, stated: “His public stance and personal place on China has been completely horrible.” He famous Mandelson was the one Labour peer to vote towards laws focusing on Chinese language “genocide” in Xinjiang.
After the vote, Mandelson instructed colleagues that having a “normal genocide definition within the formulation of international coverage” may very well be too sweeping and can be tough to use, leaving the federal government with its palms tied.

These near Starmer stated the prime minister needed to attend till Jonathan Powell, nationwide safety adviser, and Morgan McSweeney, Downing Avenue chief of employees, had met the Trump group earlier this month earlier than making a ultimate resolution.
Throughout this hiatus, some officers within the International Workplace pressed the case for Pierce, who took up her submit in Washington in 2020, to hold on, a minimum of for a yr. “She has excellent relations with the Trump group — that was an choice,” stated one authorities official.
However that was solely seen as a stop-gap resolution. “She couldn’t keep it up ceaselessly,” stated one diplomat. She is now in rivalry to turn into the primary feminine everlasting secretary on the International Workplace.
Whereas Starmer delayed, a formidable coalition of backers fashioned behind Mandelson, together with David Lammy, international secretary, Powell and McSweeney.
“Keir likes to take his time with these choices,” admitted one authorities official. “He did the identical factor with the selection of a brand new cupboard secretary and nationwide safety adviser. However ultimately the case for Peter was clear.”
Starmer accepted that having an enormous title and political operator would assist to open doorways with the Trump group. “They’ll like the truth that Peter has a popularity for ruthlessness,” stated one International Workplace insider.
Mandelson’s perception that Britain can “have its cake and eat it” by fostering good commerce relations concurrently with Washington, Brussels and Beijing chimes precisely with Starmer’s personal view that he set out in his international coverage speech at Guildhall earlier this month.
Starmer stated on Friday: “Peter will convey unrivalled expertise to the position and take our partnership [with the US] from power to power.” Lammy stated it was “fantastic to welcome Peter again to the group”.
Mandelson, co-founder of the International Counsel advisory group, stated: “It’s a terrific honour to serve the nation on this method.” He has instructed pals that he’ll put his enterprise pursuits “into chilly storage” whereas in his new job.
Lord Kim Darroch, UK ambassador to Washington through the first Trump presidency, stated most diplomats would settle for the case for inserting a political appointee into the Edwin Lutyens-designed ambassador’s residence at 3100 Massachusetts Avenue.
He instructed the FT: “These are particularly turbulent and fragile occasions. It’s not nearly Trump 2 however it’s about Ukraine, China and Nato. In these circumstances it’s good to have somebody who can actually decide up the telephone to the PM.”
For Mandelson it has been an excellent finish to the yr, following his disappointment final month at being crushed by Lord William Hague for the chancellorship of Oxford college.
On Monday he was in hospital having an operation on an aneurysm within the decrease aorta, which pals say was “completely profitable”. His new posting in Washington is predicted to begin early in 2025.