Pressure is growing on Sir Keir Starmer’s chief of staff Morgan McSweeney over his role in the appointment of Lord Peter Mandelson as US ambassador to Washington, which Labour figures accuse him of having personally spearheaded.
Multiple MPs in the party have questioned McSweeney’s judgment in the wake of the revelations about Mandelson’s behaviour and relationship with child sex offender Jeffrey Epstein, which Starmer has labelled “appalling” and “disgraceful”.
The criticism risks spreading to the prime minister himself, as one Labour frontbencher said it fuelled fresh questions about “who’s really in charge” in Number 10 and warned that the saga could shape up to be a test of the “limits of Keir’s loyalty” to his aide.
Starmer on Wednesday was challenged by Kemi Badenoch, Conservative leader, on whether he still backed McSweeney. “Of course I have confidence in him,” the prime minister told MPs.
“Morgan McSweeney is an essential part of my team. He helped me change the Labour party and win an election.”
McSweeney was for years a political protégé of Mandelson, taking strategic and personnel advice from the New Labour veteran.
Mandelson once said of the Irishman: “I don’t know who and how and when he was invented, but whoever it was . . . they will find their place in heaven.”
McSweeney used Mandelson as a sounding board during years of opposition and continued to do so in government after the 2024 election.
Many colleagues saw the influence of Mandelson in Starmer’s last reshuffle, in September, which included the sacking of soft-left MP Lucy Powell from the cabinet, a sideways move for former business secretary Jonathan Reynolds and a rebuffed attempt to move energy secretary Ed Miliband elsewhere.
Just days later Starmer sacked Mandelson as UK ambassador to the US in the wake of leaked emails showing him expressing support to Epstein after his conviction in 2008. But while some cabinet ministers wanted Mandelson fired immediately, McSweeney was initially more reluctant, according to some colleagues.
On Tuesday Wes Streeting, the Blairite health secretary, insisted that colleagues — including McSweeney — could not have known about Mandelson passing information to notorious convicted paedophile Epstein just months after he came out of jail.
“Mandelson’s relationship to Epstein or the fact he was passing sensitive and market-sensitive information to this man whilst a serving government minister — I don’t think that could have been known or should have been known,” Streeting argued.
But many backbench Labour MPs have raised the political heat on McSweeney by asking critical questions about who was advising Starmer when he gave the most senior diplomatic posting to Mandelson.
Labour MP Clive Efford said that “the key question here is who advised the prime minister? I don’t expect the prime minister to do due diligence on appointments of this kind himself, but those around him must have done.
“It does appear that there were questions that needed to be asked of Lord Mandelson and that weren’t asked, or if they were asked that the answers were not passed on.”
He demanded a guarantee from the government that “those around the prime minister who would have advised him on his appointment will be investigated fully”.
Simon Opher, a backbench Labour MP, said that while most of the anger within the party was reserved for Mandelson, who he described as an “evil person”, it nevertheless called into question “the judgment of Morgan McSweeney” for his role in bringing the peer back to frontline politics.
“If they lose the by-election I think he [Morgan] will have to go,” Opher said, referring to the upcoming vote in the seat of Gorton and Denton, considered a staunchly safe Labour seat until now.
Mandelson was forced to resign twice from Tony Blair’s government over allegations involving his friendships with ultra-wealthy individuals, and his close friendship with Epstein was known about when he was given the Washington job.
Several Labour figures claimed that McSweeney had personally championed the idea of Mandelson as ambassador, despite raised eyebrows among senior colleagues, including some officials within the Foreign Office.
Labour MP Ian Byrne this week demanded an immediate inquiry into “who knew what and when about Peter Mandelson before and during this disastrous appointment as ambassador”.
On Wednesday the opposition Conservative Party is planning to use a parliamentary mechanism known as a “humble address” to force the government to publish the full extent of the vetting process for when Mandelson became US ambassador early last year.
Foreign secretary Yvette Cooper said in September that Mandelson was not subjected to full national security vetting until after his appointment had been announced.
The FT revealed in 2023 emails suggesting that Mandelson had stayed at Epstein’s Manhattan townhouse while the disgraced financier was serving his jail sentence for soliciting prostitution from a minor. Starmer was asked about that story at a public event in January 2024, a year before he gave the job to Mandelson.
Simon Hoare, the Tory chair of the public administration select committee, is also writing to cabinet secretary Sir Chris Wormald, demanding he face questions on the vetting process.
The Conservatives said in a statement on Tuesday that McSweeney was “deeply implicated in the scandal, having known Mandelson personally for many years and having reportedly pushed hard within No 10 for his appointment — despite knowing there were concerns about his links to Epstein”.
One UK official insisted, however, that Mandelson’s appointment had made sense at the time — and that he had been instrumental in securing the UK tech and trade deals.
“I feel for Morgan because the rationale was solid. Mandelson was conversant with big business and of their tribe; with him they felt in their comfort zone. The difference between what we know of Mandelson’s links to Epstein today and what we knew of it when he was appointed is materially different,” the official said.
Another official said that neither McSweeney nor other colleagues would have backed the appointment if they had known the truth about the peer and Epstein.