In London, Mandelson’s lies were politically lethal. In the last week, Sir Keir sacked his chief-of-staff, communications director and, astonishingly, the cabinet secretary, the nation’s top civil servant. No Westminster prime minister has had such a costly scandal since Justin Trudeau lost his attorney general, president of the treasury board, principal secretary and clerk of the Privy Council (Ottawa’s equivalent of cabinet secretary) over his attempts to shield SNC-Lavalin from prosecution.