Sources say Corbyn concedes he would not have the backing to lead a unity government

Jeremy Corbyn has privately told allies that he will step aside and allow someone else to become prime minister if Boris Johnson is forced from power.

Sources say the Labour leader has concluded that he would not win the support needed to lead a government of national unity. Corbyn has signalled to allies that he might support another candidate as long as it is not a Labour or Conservative MP.

John Bercow, a Tory MP before becoming Speaker of the House of Commons in 2009, has emerged as the Labour leader’s favoured compromise candidate after he ruled out Kenneth Clarke, the former chancellor, who was expelled from the Tories last month.

One source said: “It’s not that long ago since Clarke was a member of