David Cameron has announced he will stand down as Prime Minister by October.
Here's a look at some of the potential contenders to replace him.
The former London mayor is the bookies' favourite to succeed his Old Etonian school chum at No 10. Johnson previously insisted he had less chance of taking the top job than being "reincarnated as an olive" but his protestations have done little to disguise his leadership ambitions. After leading the Brexiteers to victory his stock among the widely Eurosceptic Conservatives grassroots will be higher than ever. But Tory leadership contests have a funny habit of failing to return the dead cert.
The Justice Secretary has seen his public profile increase over the last few weeks and, bar the occasional sticky moment, he is generally regarded to have had a good campaign. Gove, whose once close friendship with Cameron has come under strain as the rough and tumble of the battle took its toll, has seen his poll ratings shoot up and Ladbrokes gives him 5/1 odds of moving into Downing Street.
Hanging on to the Home Secretary brief, which notoriously ruins political careers, for six years shows May's durability. Although a Remain supporter, she disappeared off the radar during the campaign, leaving her relatively unscathed. No fan of Cameron, she has been quietly courting the party's rank and file in readiness for his departure and is placed by the bookies as second to Johnson.
The Chancellor's hopes of moving next door have faded dramatically. An upturn in economic fortunes under his stewardship saw his popularity in the party increase but Osborne is damaged by his inextricable links to the Prime Minister. Backbenchers said his decision to back Remain ensured any leadership bid was dead in the water.
The Work and Pensions Secretary is hugely popular in the Conservative parliamentary party and comes from the sort of ordinary background that chimes with many voters. But the sudden contest may come a little too soon for him to make much headway.
The Scottish Conservative leader has impressed many with her performance during the campaign and electoral success north of the border last month. But a Westminster seat would need to be found for her to have a viable shot at the top job. Davidson has also suggested such a move is not for her, describing life at No 10 as lonely.
The Education Secretary has made no secret of her leadership ambitions, although she is viewed as an outsider by the bookmakers. She has previously said she hopes "in the not too distant future" there will be another female leader of a major party, but her choice would depend on her family. Morgan is reported to be taking soundings about throwing her hat into the ring now Cameron has announced the timing of his departure.