Boris Johnson’s time in Downing Street appears to be in its final days, but how it will end remains unclear. Robert Hazell examines the possibilities. How long will a leadership election take? Could there be a caretaker Prime Minister? What happens if Johnson tries to call a snap general election?

If Boris Johnson loses a confidence vote among Conservative MPs, he is not able to stand again. Any other Conservative MP can then stand for the party leadership. How long it will take for the party to elect a new leader will depend on the number of candidates standing, and whether the vote goes to a second stage ballot of all party members.  Party rules prescribe that Conservative MPs vote initially in a series of ballots to select two candidates, who then go forward to a postal ballot of all party members for the final decision. In 2005 it took two months for David Cameron to be elected leader, defeating David Davis in the postal ballot. In 2019 it took six and a half weeks for Boris Johnson to be elected, defeating Jeremy Hunt. It therefore seems unlikely that we will know who is the new Conservative leader (and Prime Minister) until September. But when Cameron announced his resignation in June 2016, it took just 17 days for Theresa May to emerge as the new leader, because Andrea Leadsom stood down as the second candidate in the postal ballot.

Time is being finally called on Boris Johnson’s premiership.  The initial trickle of ministerial resignations has become a steady stream; a delegation of Cabinet ministers has reportedly called on him to resign; if he doesn’t take the hint, the 1922 Committee seems likely to hold an early second confidence vote in his leadership.   But what will happen if he does resign, or if he loses the confidence of a majority of Conservative MPs?  How long might it take for the Conservative party to elect a new leader, and how will the country be governed in the meantime?