Downing Street was aware that Peter Mandelson had failed security vetting seven months before the prime minister told the House of Commons that he had been granted clearance, a Guardian investigation has revealed. The disclosure has led to the departure of Sir Olly Robbins, the top civil servant at the Foreign Office, after his department overruled the decision by security officials to deny Mandelson developed vetting.
Mandelson, who had been announced as the UK’s ambassador to the US in January 2025, failed the highly confidential background check carried out by UK Security Vetting (UKSV), a division of the Cabinet Office. Foreign Office officials then used a rarely invoked authority to override the recommendation, allowing Mandelson to take up the role.
No 10 insisted that the prime minister was not informed of the overruling until earlier this week, and that responsibility lay with the Foreign, Commonwealth and Development Office (FCDO). However, sources indicate that senior officials in Downing Street were aware of the vetting failure as early as January 2025, contradicting Starmer’s claim in September that Mandelson had been given “clearance for the role”.
The Conservative leader, Kemi Badenoch, and Liberal Democrat leader, Ed Davey, have called for the prime minister to resign if he misled parliament. The government has released 147 pages of documents on the appointment, but it can be revealed that officials have considered withholding further documents from the intelligence and security committee that would confirm the vetting denial.
A Downing Street spokesperson said the government was “committed to complying” with a parliamentary motion to release all papers relating to Mandelson’s appointment, but that any documents requiring redaction on national security grounds would be provided to the ISC. The decision on whether to withhold documents has not yet been taken.
