Who is Morgan McSweeney? Starmer’s right-hand man and Peter Mandelson ally
Morgan McSweeney has resigned as Keir Starmer’s private secretary and taken “full responsibility” for advising the prime minister to appoint Peter Mandelson as US ambassador.
It comes as Sir Keir faces growing pressure to resign amid controversy over Lord Mandelson’s links to disgraced financier and pedophile Jeffrey Epstein.
McSweeney, who has been credited as the mastermind of Labour’s landslide election victory in 2024, was seen as the driving force behind Lord Mandelson’s appointment.
His resignation was interpreted by many as an exercise in damage limitation to save Mr Starmer’s premiership.
McSweeney allegedly had knowledge that Mandelson’s dealings with Epstein continued after the financier was convicted of child sex crimes.
As the prime minister’s right-hand man, Mr McSweeney was central to the government’s strategy and decision-making.
As a result, he was seen by some as responsible for Downing Street’s failed attempt to control the publication of potentially explosive documents detailing the appointment decision.
“The decision to appoint Peter Mandelson was wrong,” he wrote in a statement announcing his resignation on Sunday. “It damaged the trust in our party, our country and politics.”
In the letter, McSweeney called for an overhaul of the investigation system, writing: “While I have not overseen the due diligence and review process, I believe this process must now be fundamentally overhauled. This cannot be just a gesture, it can be an assurance for the future.”
Who is Morgan McSweeney?
Mr McSweeney was born in County Cork but left Ireland in 1994, aged 17, for London, where he is said to have initially worked on building sites.
He joined the Labor Party in 1997 because of support for the Good Friday Agreement, which was key to the Northern Ireland peace process.
According to his Linkedin profile, he took a job as a Labor Party conference manager in June 2001.
Reports say he was later recruited to work in Labour’s “attack and rebuttal unit” at the party’s Millbank headquarters, where he was tasked with adding information to the “excalibur” database that informs Peter Mandelson’s campaign messages.
It is also said that he was sent to campaign in marginal seats during the 2005 general election as his reputation as an effective organizer and operator began to grow.
He was seen as a key figure in the successful attempt, led by current Communities Minister Steve Reed, to unseat the coalition of Liberal Democrats and Conservatives in the London borough of Lambeth.
After failing in his bid to become a councilor in Sutton in 2006, he was appointed head of Mr Reed’s leadership office in Southwark, a position he held until October 2007.
After serving as communities manager at consultancy The Campaign Company, Mr McSweeney joined the Local Government Association as a political adviser and was later appointed head of the organisation’s Labor Party group office, a role he held until 2017.
During this time, he ran Liz Kendall’s leadership campaign in 2015, which resulted in the current Science Secretary coming in fourth.
Mr McSweeney was appointed director of the Labor Together think tank in 2017, sharing a seat on the board with Mr Reed and current Culture Minister Lisa Nandy.
At the time, he was said to have announced his intention to move the party, then led by Jeremy Corbyn, from the “hard left” and “build a sustainable, winning electoral coalition”.
But Mr McSweeney later came under scrutiny for financial irregularities during his tenure at Labor Together.
In 2021, the Electoral Commission fined the think tank £14,250 for failing to submit donation reports within 30 days, incorrectly reporting donations and failing to appoint a responsible person within 30 days of accepting the donation.
The Conservatives called on the regulator to re-examine the case in September last year after emails apparently sent to Mr McSweeney by a Labor Together lawyer were leaked.
The regulator said its review of the information did not provide “evidence of any other potential wrongdoing”, despite Conservative Party chairman Kevin Holinrake suggesting the emails could be evidence that the Electoral Commission had been misled.
Mr McSweeney was appointed to run Sir Keir’s successful 2020 leadership campaign and initially became his private secretary.
But following Labour’s poor showing in the Chesham and Amersham by-elections in 2021, he has been appointed to a strategic role in the leader’s office but is said to remain as a key adviser.
After being appointed as Labour’s campaign director in September 2021, Mr McSweeney is said to be behind an effort to impose a new central parliamentary candidate list in what is seen as an attempt to exclude those to the left of the party.
Labour’s election victory in 2024 resulted in Mr McSweeney being appointed to the joint role of head of political strategy.
Later reports suggested tensions had developed between Mr McSweeney and then-chief of staff Sue Gray, but Labor Party sources gave conflicting views about the relationship at the time.
Following Ms Gray’s resignation, Mr McSweeney was appointed Downing Street chief of staff in October 2024.
Mr Starmer said of his resignation: “It was an honor to work with Morgan McSweeney for many years. He turned our party around from one of its worst ever defeats and played a central role in the running of our election campaign.”
