Prime Minister Keir Starmer came under fierce attack from opponents across the political spectrum on Friday after revelations that Peter Mandelson failed government security vetting before his appointment as UK ambassador to the United States.

The Guardian first reported on Thursday that Mandelson, a Labour peer and close ally of Tony Blair, was denied Developed Vetting clearance in late January 2025 following concerns over his ties to the late sex offender Jeffrey Epstein. Despite the recommendation against clearance from UK Security Vetting in the Cabinet Office, Foreign Office officials overruled the decision and granted him access anyway, allowing him to take up the post on February 10, 2025.

Mandelson served in the role for seven months before Prime Minister Starmer sacked him last September amid scrutiny over his Epstein connections and allegations of leaking government documents. Starmer had repeatedly assured Parliament that "full due process" had been followed, including statements at Prime Minister's Questions in September 2025 and in February this year.

A government spokesperson confirmed Friday that neither Starmer nor any minister knew of the vetting failure or the override until earlier this week. Starmer, who learned of the issue on Tuesday evening, instructed officials to investigate immediately. He described the nondisclosure as "staggering" and "unforgivable," stating: "That I wasn’t told that he’d failed security vetting when I was telling parliament that due process had been followed is unforgivable. Not only was I not told, no minister was told and I’m absolutely furious about it."

In response, Starmer effectively sacked Sir Olly Robbins, the permanent under-secretary at the Foreign, Commonwealth and Development Office, after losing confidence in him late Thursday evening. Foreign Secretary Yvette Cooper and Starmer met with Robbins before concluding he could no longer remain in post.

Opposition leaders seized on the scandal. Conservative chief Kemi Badenoch said Starmer either lied to Parliament or proved "hopelessly incompetent." Reform UK's Nigel Farage called Robbins a "sacrificial lamb" and demanded Starmer stand down. SNP's Stephen Flynn labeled Starmer "incompetent, gullible or a liar," urging resignation. Liberal Democrat Ed Davey accused Starmer of breaching the ministerial code, while Greens and Plaid Cymru echoed calls to quit.

Some Labour figures expressed unease. MP Diane Abbott said Starmer should "consider his position," while Emily Thornberry felt "misled" by Robbins. Backbencher Jon Trickett questioned the credibility of claims Starmer was unaware. Starmer plans a full statement to the Commons on Monday, promising transparency with documents potentially reviewed by the Intelligence and Security Committee.

Mandelson has not commented publicly and was seen walking his dog in London on Friday. The episode adds to challenges for Starmer's government, already hit by the fallout from Mandelson's earlier dismissal.