Starmer’s UK Premiership Teeters on Brink as Key Aides Quit

(Bloomberg) — Keir Starmer’s future is in the balance after a crisis over the appointment of Peter Mandelson as ambassador to Washington claimed the UK prime minister’s closest aide.

Morgan McSweeney quit as chief of staff on Sunday, saying he took “full responsibility” for his advice to hire the Labour veteran as US envoy, despite Mandelson’s known ties to the convicted pedophile financier Jeffrey Epstein. He was followed out of Downing Street by Tim Allan, who quit as Starmer’s director of communications. But it isn’t lost on Starmer’s allies and opponents alike that the man who actually appointed Mandelson remains in post.

Most Read from Bloomberg

No. 10 officials were bracing for cabinet ministers to privately tell the premier to stand aside or threaten their resignations if he doesn’t, according to people familiar with the matter who spoke anonymously in order to be candid about the turmoil at the top of the Labour Party. One aide to a cabinet minister said it was 50-50 whether Starmer would last the week.

Starmer deliberated for days over whether he could afford to carry on without McSweeney, a person familiar with those discussions said. Losing the mastermind of Labour’s 2024 election landslide leaves the prime minister exposed at a time when frustrated members of government are braying for change at the top, with Health Secretary Wes Streeting and former Deputy Prime Minister Angela Rayner touted as contenders to succeed him.

“It’s in his hands,” Labour MP Andy McDonald said of Starmer’s future on the BBC’s Today program on Monday. “If he doesn’t own the error he’s made and recognize the problem in front of him and articulate it and tell us how he’s going to deal with it, then I’m afraid it is coming to an end — if not today, certainly in the weeks and months ahead.”

Allan seemed to hint at wider changes yet to come, saying he was standing down “to allow a new No. 10 team to be built.”

With McSweeney for so long a lightning rod for controversies engulfing the prime minister, Starmer will also be unshielded at a time when the Mandelson furor may be far from over. Members of Parliament recently secured the publication of vetting documents around the diplomatic appointment. That material has yet to land.

Within the governing party, some expect Starmer to try to shore up his position by inviting left-wing figures such as Rayner back into the cabinet and promoting the likes of Energy Secretary Ed Miliband, himself a former party leader. But others doubted Rayner would accept a job because she is now a step closer to taking Starmer’s. The only way he can survive until May’s local elections is as a lame duck with his rivals using that time to prepare their challenges, one Labour official said.

There was astonishment among Starmer’s longest-standing supporters that the weakened prime minister had let McSweeney go. On Saturday, Starmer’s close allies had been saying his chief of staff wouldn’t resign because that would make the leader’s downfall inevitable. As late as Sunday morning, cabinet minister Pat McFadden told Sky News that he didn’t think McSweeney should take the hit over what was ultimately a “prime ministerial appointment.”

The renewed speculation over Starmer’s position knocked gilts again, Monday morning — yields on the government bonds rose as much as four basis points across the curve, with 10-year yields up to 4.55%.

Investors tend to react negatively to the prospect of Starmer or Chancellor of the Exchequer Rachel Reeves leaving their posts, out of concern they could be replaced by colleagues less committed to fiscal rigor.

The pound was little changed against the dollar at around $1.36 on Monday, and fell 0.5% against the euro, trading near a more than two-week low.

“It’s not good for the country to change its prime minister every 18 months or two years,” McFadden told Sky News on Sunday. “It’s leading to chaos and uncertainty economically, politically and reputationally around the world.”

Even if Starmer survives the clamor for accountability around Mandelson, he faces jeopardy in the coming weeks. The most imminent flashpoint is a Feb. 26 special election in Gorton and Denton, a constituency which ought to be a Labour stronghold but where the Greens and Reform UK are now vying for first place. Just over two months later follows a wider set of local elections where polls suggest Labour will hemorrhage seats.

After losing his second chief of staff in just 19 months, Starmer moved swiftly to promote McSweeney’s former deputies, Jill Cuthbertson and Vidhya Alakeson to jointly fill the vacated role. His office indicated the prime minister is likely to make an intervention on Monday to update the country on his next steps to deliver the change promised by his party in 2024.

He has voiced frustration in recent days over how the Mandelson crisis is distracting from that agenda. The latest ructions were sparked by revelations that the former member of the House of Lords appeared to have leaked sensitive government information to Epstein while serving as a minister more than 15 years ago. Mandelson is also coming under pressure to return money he received as part of his sacking as ambassador.

The situation has put fresh scrutiny on Starmer’s judgment in appointing someone who’d twice resigned from government in controversial circumstances and was nicknamed the Prince of Darkness because of his mastery of political manipulation.

One previously loyal supporter of Starmer said they expected him to now be forced out. Last year’s welfare-policy U-turn had been the beginning of the end for the premier by displaying his weak command of his party and lack of conviction in his own project, they said. Another erstwhile Starmer supporter said Labour had let the country down by behaving no better than the Tories they replaced, despite campaigning to restore decency to politics.

Critics were circling on Sunday when two key Labour-linked groups suggested responsibility for Mandelson’s appointment shouldn’t end with the chief of staff.

Mainstream, a network of left-leaning Labour politicians, said: “All those involved” in Mandelson’s appointment “must be held to account.” Compass, another left-wing pressure group, was blunter: “In time, a new captain will be needed to steer the party.”

Opposition parties also wasted no time in turning the focus on Starmer. “The buck stops with him,” said Deputy Leader of the Liberal Democrats Daisy Cooper, while main opposition Conservative Party Leader Kemi Badenoch said on X that Starmer should “take responsibility for his own terrible decisions.” Nigel Farage, the populist leader of the poll-leading Reform UK Party, predicted that the premier “won’t be far behind” McSweeney.

In the House of Commons the displeasure from Labour’s own ranks was on display this week when the party’s backbenchers — led by Rayner — opposed government efforts to water down a Tory motion seeking the disclosure of documents relating to Mandelson’s appointment and tenure as ambassador. The rebels got their way, and the government is now preparing to disclose thousands of pages of information, though no date has yet been set for publication.

Rayner is now seen as the front-runner to become premier, but Labour figures tipped at least six others to go for the job, including Miliband, Streeting, Home Secretary Shabana Mahmood and Foreign Secretary Yvette Cooper. Several people on the Labour right suggested Defense Secretary John Healey should take over.

–With assistance from Shiyin Chen, Valentine Baldassari, Joe Mayes and Alice Gledhill.

(Updates with departure of communcations chief in second paragraph.)

Most Read from Bloomberg Businessweek

©2026 Bloomberg L.P.