The flare-up of the Mandelson scandal threatens Sir Keir Starmer’s political future (Image: Getty) Sir Keir Starmer is facing calls to quit so the Government will not be distracted by a “personal crisis of his own making” following the latest revelations about Peter Mandelson’s appointment as US ambassador. The Labour leader’s future could hinge on the expected appearance before MPs on Tuesday by Olly Robbins. The former top civil servant at the Foreign Office was ousted on Thursday amid claims his department did not tell the Prime Minister that Mandelson had failed security vetting. Sir Keir will stand before MPs on Monday and detail how Mandelson – a former close friend of billionaire sex predator Jeffrey Epstein – was granted the top diplomatic post. The PM claims “no minister was told” that this veteran of the Blair and Brown governments had failed the vetting process. A Labour MP told the Sunday Express: “If that is proven incorrect then I think we are talking resignation time, to be honest.” The MP said the evidence that Mr …