Britain’s former US ambassador Peter Mandelson failed his security vetting before taking up the role, but Prime Minister Keir Starmer was unaware officials had overruled the recommendation, the government said on Thursday. “Neither the prime minister, nor any government minister, was aware that Peter Mandelson was granted developed vetting against the advice of UK Security Vetting until earlier this week,” a government spokesman said in a statement. The decision was taken by officials in the...