UK Prime Minister Sir Keir Starmer has expressed frustration over the abrupt sacking of Peter Mandelson as ambassador to the United States, amid revelations of his close ties to convicted sex offender Jeffrey Epstein, setting the stage for a heated parliamentary debate just hours before President Donald Trump's state visit.

The controversy erupted last week when U.S. congressional documents revealed Mandelson's affectionate messages to Epstein, including a 2003 birthday book entry calling him "my best pal" and 2008 emails expressing sympathy after Epstein's conviction for procuring a minor for prostitution, suggesting it was wrongful and offering to challenge it.

Mandelson, appointed in January 2025, was dismissed Thursday after the Foreign Office deemed the relationship's depth "materially different" from what was known during vetting. Starmer defended him Wednesday at Prime Minister's Questions, stating full confidence, but reversed course within 24 hours.

In his first public comments Monday to Channel 4 News, Starmer said he was "angry" at the situation and would not have appointed Mandelson if aware of the details beforehand. He claimed No. 10 was unaware of the emails prior to PMQs and had not inquired further. The government declined to release vetting documents, fueling calls for transparency. Commons Speaker Sir Lindsay Hoyle granted Conservatives a three-hour emergency debate Tuesday, focusing on what Starmer and officials knew about Mandelson's Epstein links.

The timing complicates Starmer's efforts to strengthen U.S. ties during Trump's visit, which includes pomp and ceremony at Buckingham Palace. Trump, whose own Epstein associations have resurfaced, met Mandelson at the White House in May. Former Prime Minister Gordon Brown defended Starmer, expecting him to be "exonerated" and noting the challenges of tough decisions. Conservatives, led by Kemi Badenoch, demand full disclosure of Mandelson's correspondence and questioned Starmer's judgment, with Badenoch calling it "more strikes, more scandal, more chaos."

Mandelson, in a podcast appearance, acknowledged more "very embarrassing" details would emerge but regretted the association, describing Epstein as a "charismatic criminal liar" and denying witnessing wrongdoing. He attributed not seeing Epstein's crimes to his sexuality as a gay man and said he ended contact after 2008. Labour MPs like Bell Ribeiro-Addy and Kim Johnson called for his resignation, while U.S. lawyer Gloria Allred, representing Epstein victims, sought his congressional testimony.