Prime Minister Keir Starmer faced a mounting political crisis on Monday as his director of strategy resigned over crude messages from 2017 and the prime minister acknowledged he had known about Lord Peter Mandelson’s friendship with convicted sex offender Jeffrey Epstein when he appointed the former minister as UK ambassador to the United States.

Paul Ovenden resigned from his role at No. 10 after messages he sent in 2017, published by the Daily Mail, were revealed to contain crude sexual remarks about Labour MP Diane Abbott. Downing Street described the messages as "appalling and unacceptable." The departure follows the recent resignations of Lord Mandelson and, separately, the sacking of other senior figures since the government’s relaunch earlier this month.

Starmer told Channel 4 News he was "angry" and felt "let down" by the newly revealed material and by what he described as a lack of candour from people around him. He said he regretted appointing Lord Mandelson and that, had he known the full extent of the information at the time, "I wouldn't have appointed him."

Downing Street confirmed that the prime minister had known of a friendship between Mandelson and Epstein, including that Mandelson had stayed at Epstein's home while Epstein was in prison for child sex offences. Starmer also said he had been aware the Foreign Office was investigating additional emails between Mandelson and Epstein when he defended Mandelson in the Commons last week, though he said he did not know the contents of those emails at the time.

Conservative leader Kemi Badenoch accused the prime minister of going into hiding after initially defending Mandelson and then sacking him less than 24 hours later. The Conservatives have requested the release of documents they call the "Mandelson files" to clarify what the government knew and when. They also secured an emergency Commons debate on the matter.

Labour figures expressed alarm at the rapid series of controversies. Some MPs privately warned that the prime minister has "months" to restore confidence; Labour backbencher Helen Hayes said there would be "questions about the nature of the leadership" if local election results in England, Scotland and Wales next May again disappoint. Former frontbencher Andy McDonald said party morale was "very low" and called for a shift in direction from the leadership.

The developments come less than two weeks after Starmer announced a "Phase Two" reset intended to focus the government on delivery. Instead, the prime minister has lost multiple senior figures amid public scrutiny and intraparty tensions. Pressure has also grown on Starmer's chief of staff, Morgan McSweeney, who had championed Mandelson's appointment; several MPs called for changes in Downing Street's senior team.

Mr. Ovenden had been a speechwriter and a leader of Labour's attack unit during the party's opposition years. Allies described him as a popular figure inside No. 10. His resignation follows reports that the messages in question were written while he was at the Labour Party.

The controversy has reverberated beyond personnel moves. Ministers scrambled to manage other high-profile items on the calendar, including arrangements for an anticipated state visit by former U.S. President Donald Trump. Reform UK said it had secured a defection by former Conservative MP Danny Kruger, a development the party said reflected wider discontent in Westminster, a claim the Conservatives did not immediately confirm.

Starmer said he would not resign. He faces ongoing scrutiny from opposition parties and some within his own ranks as further inquiries and parliamentary scrutiny proceed over the Mandelson-Epstein correspondence and the circumstances surrounding recent appointments and departures.