UK PM Keir Starmer says he was not informed that Peter Mandelson failed his security vetting before being appointed US ambassador, calling the omission 'staggering.' The Foreign Office overruled vetting officials to grant Mandelson clearance despite the initial rejection, and opposition MPs are now questioning whether Starmer's claim of ignorance is credible or if serious governance failures occurred at the civil service level. The story is also raising fresh scrutiny of Mandelson's Epstein connections, which featured in the security concerns. This puts immediate pressure on Starmer ahead of local elections and raises questions about who knew what and when within Downing Street and the Foreign Office.