Almost all officials working in Foreign Office HQ undergo process before gaining access to top secret material Almost all officials working in Foreign Office HQ undergo process before gaining access to top secret material After Keir Starmer announced Peter Mandelson as his pick to be ambassador to the US in December 2024 , officials in the Foreign Office contacted him to organise the security vetting clearance process. As with almost all of the 8,000 officials working in the Foreign Office’s