Addressing the nation just after midday on Thursday, Mr Johnson offered his resignation but said he intended to remain in office until his successor is elected, a process which could take months.
"Now I hope to answer the call once again as prime minister. It's time for a clean start. It's time for renewal."
But Deputy Prime Minister Dominic Raab and Michael Gove have both ruled themselves out of the contest, Sky News had been told. Speaking before Mr Johnson resigned on Thursday, Attorney General Suella Braverman told ITV's political editor Robert Peston that"yes" she would hypothetically consider a leadership bid if the PM was to stand aside.While Business Secretary Kwasi Kwarteng also hinted that he will throw his hat in the ring.
The timetable for the leadership contest is expected to result in a successor being in place for the party's conference in October.
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