Morgan McSweeney resigned Sunday as chief of staff to British Prime Minister Keir Starmer, following mounting backlash over his role in recommending Peter Mandelson for the post of United Kingdom ambassador to the United States. The resignation comes amid growing scrutiny of Mandelson’s past ties to convicted sex offender Jeffrey Epstein.

In a resignation statement obtained by The Guardian, McSweeney acknowledged that advising Mandelson’s appointment was a serious mistake and accepted full responsibility for the decision. He described stepping down as the “only honourable course” given the damage caused to public confidence.

“He has damaged our party, our country, and trust in politics itself,” McSweeney wrote of Mandelson, adding that the decision to resign was not taken lightly. McSweeney also called for a comprehensive overhaul of the government’s vetting and due diligence procedures, while pledging continued support for Starmer and the Labour government’s broader agenda.

The controversy intensified after emails and documents released by the U.S. Justice Department in January revealed that Mandelson maintained contact with Epstein after Epstein’s 2008 conviction on two felony prostitution charges, one involving a minor. Additional reporting by the Associated Press indicated Mandelson may have shared sensitive government information with Epstein following the 2008 global financial crisis.

According to the AP, financial records also show Epstein transferred a combined $75,000 in 2003 and 2004 to accounts connected to Mandelson or his husband, Reinaldo Avila da Silva. Mandelson has not been charged with any crime related to Epstein.

The issue reached Parliament last month, when Foreign Office minister Stephen Doughty told the House of Commons that Starmer ordered Mandelson’s withdrawal from the ambassador post after new information emerged about the nature of his relationship with Epstein. Doughty said Mandelson’s claim that Epstein’s first conviction was wrongful represented a significant departure from what officials understood at the time of the appointment.

“In the light of that and mindful, as we all are, of the victims of Epstein’s appalling crimes, Lord Mandelson has been withdrawn as ambassador with immediate effect,” Doughty said.

Mandelson resigned from the Labour Party on Feb. 1. The episode has added pressure on Starmer’s leadership and raised broader questions about accountability, transparency, and judgment within the Labour government’s senior ranks.