Senior cabinet ministers are rallying around UK Prime Minister Keir Starmer, whose leadership is threatened by naming Peter Mandelson, a figure linked to Jeffrey Epstein, as ambassador to the United States.

Senior Cabinet ministers on Sunday rallied around UK Prime Minister Keir Starmer, whose leadership is teetering over his decision to give Britain’s most important diplomatic job to Peter Mandelson, a scandal-tarnished politician and friend of Jeffrey Epstein. Starmer will face restive lawmakers in Parliament on Monday to fight for his job after the explosive revelation that Mandelson was appointed ambassador to the United States despite failing security checks. Starmer says he is “furious” that....