Enough Tory MPs have now requested a vote of confidence in Theresa May to trigger a leadership contest. Among the likely runners and riders is former London Mayor and Uxbridge MP Boris Johnson.
Prominent Brexiteer and former Foreign Secretary Boris Johnson (joint favourite at 5-1 with Ladbrokes) is a leading voice of opposition to Mrs May's Brexit plan.
The colourful Old Etonian was one of the key players in the 2017 Leave campaign and resigned from the cabinet following the Chequers summit in July.
He was heavily tipped as a successor to David Cameron but ruled himself out of the 2016 leadership contest after Michael Gove made a last-minute bid for the top job.
In a diary piece for the Spectator, Mr Johnson compared his former "late night binges of chorizo and cheese" and recent weight loss to Brexit: "We know that we have to make certain changes if we are to leave the EU."
Mr Johnson refused to rule out challenging Theresa May for her premiership in at interview at the weekend, saying the British people should not "underestimate the deep sense of personal responsibility I feel for Brexit"'. Mr Johnson, 54, who was Mayor of London for eight years, recently announced his divorce from his wife Marina Wheeler, a human rights lawyer.