The Foreign Office’s most senior civil servant Sir Olly Robbins is to leave his role following revelations that the department overruled security vetting for Lord Peter Mandelson’s appointment as UK ambassador to the US.

It is understood that Sir Keir Starmer and Foreign Secretary Yvette Cooper have expressed a loss of confidence in Sir Olly, the permanent under-secretary.

Security officials had initially denied clearance for the Labour peer, but Foreign Office officials took the unusual step of overriding this recommendation.

The Prime Minister was reportedly unaware until earlier this week that Lord Mandelson had been granted developed vetting against the advice of UK Security Vetting.

He has since instructed officials to establish the full facts surrounding the decision, with the Foreign Office stating it is “working urgently” to comply with the inquiry.

More to follow…