David Cameron has said he intends to stand down as Conservative Party leader and prime minister following the UK’s decision to leave the EU and says his successor should be elected by the time of the party’s conference in October. So what are the rules and who are the leading candidates?
The Conservative leadership election rules
The party’s 1922 committee will oversee the contest and is expected to follow the system used to elect David Cameron in 2005. However, this will have to be approved by the Conservative Party’s board.
MPs wanting to stand need to be nominated by two others to get onto the ballot paper. If there are three or more candidates, a ballot or series of ballots will be held of all the party’s 331 MPs to whittle down the field to two. In each round, the candidate with the fewest votes will be eliminated.
After that, a vote of the wider party – in which all Conservative members will have a say – will be held to choose the winner.
If the party is to have a new leader in place in time for its autumn conference, which starts on 2 October, the initial ballots will have to be held before Parliament breaks up for its summer recess on 21 July. There would then be a series of hustings over the summer before a decision in September.
Although Mr Cameron has said he wants the new leader in place for the Conservative conference, the timetable has not yet been agreed.
The former mayor of London has immediately been installed as the bookies’ favourite to be the next occupant of Downing Street.
The 52-year-old journalist-turned-Conservative politician is one of the most familiar faces in British politics, his unconventional political style and unique brand of charisma making him a household name.
Long thought to harbour ambitions to be prime minister, his rivalry with David Cameron – both are products of Eton and Oxford – has been the subject of much speculation over the years.
Mr Johnson, who spent eight years in City Hall before re-entering Parliament last year, backed the right horse in the EU referendum fight although some in the party questioned his reasons for doing so.
While he is regarded as being an electoral asset – his ratings in London’s mayoral elections exceeded his party’s – it remains to be seen whether enough Conservative MPs believe he has the right temperament and political judgement for the top job – particularly given the uniquely trying circumstances in which the next leader will take office.
Unlike Mr Johnson, the 48-year-old has gone out of his way in the past to put a limit on his personal ambitions, even going so far as to suggest that he was not equipped to do the job of prime minister.
The former Times journalist, who entered Parliament in 2005, has been a close personal friend of David Cameron and George Osborne and was a key figure in the party’s modernisation that led to its return to power in 2010.
He subsequently became a reforming, if controversial, education secretary and is regarded as one of the party’s intellectual heavyweights.
The justice secretary’s decision to back the Leave side was one of the key turning points in the campaign and although it is said to have strained his relations with Mr Cameron, he is still respected on both the Remain and Leave wings of the party and is likely to be a pivotal figure in the coming months.
One of the longest-serving home secretaries in history, who turns 60 later this year, has long been mentioned as a potential future leader of the party.
Mrs May, who famously once described the Conservatives as the “nasty party” in the fallow years after its 1997 landslide defeat, is one of Whitehall’s toughest and shrewdest operators.
The MP was praised for her unflappable handling of the often problematic Home Office brief – regarded as something of a poisoned chalice – although her wider political appeal has yet to be tested.
While coming out for Remain, Mrs May – who revealed in 2013 that she suffers from type 1 diabetes – maintained a relatively low profile during the campaign, meaning that she could potentially appeal to MPs looking around for an “anyone but Boris” candidate.
Many commentators believe David Cameron’s right-hand man and political soulmate yearns to move the short distance to No 10 from 11 Downing Street – where the 45-year-old has spent the last six years as chancellor.
Both Gordon Brown and John Major made similar journeys but Mr Osborne faces formidable challenges if he is to follow them.
Although he has a strong power base in Parliament – so-called “friends of George” occupy many of the seats around the Cabinet table – his stock among backbenchers on the right of the party has never been so low and his fortunes have been closely entwined with Mr Cameron’s.
While many admire his handling of the economy, there were already question marks before the EU referendum about his political judgement following U-turns over disability benefit cuts, Sunday trading reforms and school academies.
His high-profile backing of the Remain cause, which culminated in his warning that there would have to be a tax-raising emergency Budget in the wake of a Brexit vote, means he’d have a long way to go to win back the Eurosceptic side of the party.
One of the rising stars of the Conservative Party, and the first Conservative cabinet minister for generations to sport a beard, the 43-year-old has a back story to which many Tory MPs are attracted.
Raised by a single mother on a council estate, the Welsh politician has spoken openly about his family’s dependence on benefits and the importance of work, education and his Christian faith in promoting self-reliance and economic independence.
After becoming an MP in 2010, Mr Crabb was promoted to the Cabinet in 2014 as Welsh secretary. His profile went up a notch earlier this year when he took over as work and pensions secretary following Iain Duncan Smith’s resignation.
It remains to be seen whether this opportunity comes too early and whether his support for Britain to remain in the EU will hold him back.
Other possible candidates:
Nicky Morgan: The education secretary is reported to be taking soundings on whether to throw her hat into the ring, saying it would “be good” to have a woman in the final two on the ballot paper. On the centre-left of the party, her strong support for a Remain vote may put her at a disadvantage.
Sajid Javid: The business secretary and former merchant banker, the son of a Pakistani-born bus driver, has shot up the ranks in recent years. But he was criticised for his handling of the Tata steel crisis and his decision to back the Remain campaign despite previously expressing strong Eurosceptic views.
Liam Fox: It could be second time around for the former defence secretary. The former GP came a close third in the 2005 leadership contest but his Cabinet career was cut short in 2011 following a lobbying row. He was a forceful voice for Brexit on the backbenches but also for Conservative unity after the poll.
Andrea Leadsom: The former banker and fund manager was one of the stars of the Leave campaign, giving a composed performance as she took her place alongside Boris Johnson in its debating team. Whether she stands or not, the energy minister could be bound for a cabinet job before too long.
Dominic Raab: Leadership fights often throw up unexpected names and could the 42-year-old be the surprise package of the contest. The justice minister and former solicitor is media-friendly and was a key figure behind the scenes in the Leave campaign.
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