Sir Olly Robbins, the most senior civil servant at the UK's Foreign, Commonwealth and Development Office (FCDO), has been forced to resign after it emerged that his department overruled a security vetting rejection of Peter Mandelson, who was subsequently appointed Britain's ambassador to the United States. Security officials had initially denied Mandelson clearance in late January 2025 following a confidential background check, but FCDO officials invoked a rarely used authority to override that recommendation — a decision taken just weeks after Robbins assumed the permanent secretary role. Prime Minister Keir Starmer, who aides say only learned of the failed vetting this week, lost confidence in Robbins alongside Foreign Secretary Yvette Cooper, with Downing Street emphasising that responsibility for the override lay solely with Foreign Office officials.