Sir Keir Starmer is facing mounting pressure after reports that Lord Mandelson was appointed as UK ambassador to the United States despite initially being denied security clearance.
A new investigation by The Guardian found that Lord Mandelson failed developed vetting in late January 2025, a high-level security check required for access to sensitive intelligence and diplomatic material.
According to the report, the decision was subsequently overturned by the Foreign Office using rarely used powers, allowing him to take up the role in Washington.
The Prime Minister had already announced the appointment in December 2024, before the vetting process had been completed.
The developments have raised fresh questions about the government’s handling of the appointment, particularly after repeated assurances from ministers that proper procedures had been followed.
Conservative leader Kemi Badenoch said:
“Last September, Keir Starmer told Parliament three times that ‘full due process’ was followed over the appointment of Lord Mandelson.
“We now know the Prime Minister misled the House. The Prime Minister must take responsibility.”
The controversy adds to earlier concerns over Lord Mandelson’s links to Jeffrey Epstein. He was removed from a government role in September 2024 after emails emerged detailing continued contact with Epstein following his conviction for child sex offences.
Lord Mandelson was later arrested on suspicion of misconduct in public office, relating to allegations that he shared government material with Epstein while serving as business secretary under Gordon Brown. He denies any wrongdoing and remains under investigation.
The Guardian also reported that officials have discussed whether to withhold documents from Parliament which could confirm that Lord Mandelson was initially refused vetting clearance, despite a motion requiring the release of information related to the appointment.
Further disclosures are expected in the coming days, with additional documents due to be published.
Downing Street has previously insisted that “due process was followed”, but the latest revelations are likely to intensify scrutiny of the Prime Minister’s account of events.
