Theresa May is set to fight for her political life on Wednesday night as Tory MPs declare whether they have confidence in their embattled leader.
Sir Graham Brady, the Conservative MP in charge of leadership contests, revealed early on Wednesday morning that he had received at least 48 letters from Tory MPs saying they no longer backed the prime minister, thereby triggering a vote of no confidence.
The announcement came just two days after May controversially shelved a key vote by parliament on her Brexit deal that she admitted she would have lost.
Speaking on the steps of Number 10 today, the PM pledged to fight off the attempt to oust her from power with “everything I’ve got”.
But who would take her place if she fails? We take a look at the potential candidates for the top job.
YouGov polling from May through to October puts Boris Johnson on level pegging with May staying in place.
And here are the latest bookies odds.
One favourite to take the helm is Dominic Raab, who resigned as May’s Brexit Secretary a few weeks ago.
A former chief-of-staff to his predecessor in the role, David Davis, Raab nailed his colours to the mast during negotiations by demanding the UK have the right to unilaterally end the Northern Ireland backstop arrangement.
Raab briefly served as housing minister and justice minister before being promoted but has long been regarded as capable of high office.
A former lawyer, Raab has previously worked in the Foreign Office leading a team of Embassy officials in the Hague dedicated to prosecuting war criminals.
Crucially for his political future in the Conservative Party, he campaigned to leave the European Union during the 2016 referendum but, having served also as Remainer Dominic Grieve’s chief-of-staff, Raab will have reach beyond Eurosceptics.
However, some eyeing an early general election may view Raab as easy prey for Labour.
He admitted he did not understand how heavily the UK relied on the Dover to Calais crossing, has claimed food bank users have a “cash flow problem” and put his name to a paper which claimed British workers are “among the worst idlers in the world”.
The 44-year-old is also a black belt in karate.
Bookies odds – 11/2
The Rochdale-born son of a Pakistani bus driver who became home secretary is now hotly tipped to become prime minister.
Javid has an impressive back story. Comprehensive school-educated, he graduated from Exeter University, where his contemporaries included key Tory influencers Tim Montgomerie and Robert Halfon, to become vice president of Chase Manhattan Bank aged just 25.
Since being elected MP for Bromsgrove in 2010, he has held a series of ministerial positions, including Business Secretary under David Cameron and Communities Secretary in the wake of the Grenfell Tower disaster.
He replaced Amber Rudd as Home Secretary in April after the Windrush scandal.
He campaigned against Margaret Thatcher’s decision to join the European Exchange Rate Mechanism, which led many to hope he would campaign for Brexit.
He remained loyal to David Cameron, however, as he has to Theresa May – which may be both a blessing or a curse when he asks a divided set of Tory MPs to back him.
An unashamed Thatcherite, his favourite author is Ayn Rand.
Bookies odds – 9/2
The International Development Secretary campaigned for Brexit but has remained studiously loyal to the Prime Minister since being promoted to the cabinet.
The daughter of a paratrooper and a special needs teacher, Mordaunt is a naval reservist and has a dual role serving also as women and equalities minister, meaning her appeal could be broad.
Once head of broadcasting for the Conservative Party under William Hague and a former contestant on the ITV reality show Splash! Mordaunt will be adept at handling the glare of publicity.
Her Leave credentials will put her ahead of some of her colleagues but remainers will have reservations.
During the referendum campaign - while a defence minister - she sparked a furious row by telling the BBC’s Andrew Marr Show that the UK could not veto Turkey joining the EU. David Cameron corrected her an hour later.
Bookies odds – 14/1
The Environment Secretary has long harboured ambition for the leadership and stood briefly in 2016.
Privately skeptical of May’s Brexit plans, he is said to take the view that future governments can push to diverge from the EU after March.
Gove has a reputation as a reformer and since being taken back into the Cabinet fold has thrown his weight behind boosting animal welfare and measures to ban plastics.
However, many Tory MPs still view Gove with suspicion after he knifed his fellow Brexiteer Boris Johnson by withdrawing support and standing himself.
Bookies odds – 8/1
The former London Mayor remains the darling of the Brexit-backing Tory membership, despite a dreadful tenure as foreign secretary.
But that won’t help him with Tory MPs, whose backing he will need to make it to the final two of a leadership race.
Many have spoken out against a number of divisive and/or offensive statements Johnson was behind.
They range from comparing hijab-wearing Muslim women to letterboxes or bank robbers or ‘joking’ that the Libyan capital of Sirte could be regenerated once “the dead bodies” were removed.
Such conduct means that despite the platform he his Telegraph column, for which he is reportedly paid £275,000-a-year, affords him and his near-celebrity status with the public, MPs are unlikely to be persuaded he is a serious candidate.
Johnson also bottled a leadership run in the wake of the Brexit referendum when Michael Gove, his fellow Vote Leave campaigner stood against him, saying he had “come, reluctantly, to the conclusion that Boris cannot provide the leadership or build the team for the task ahead”.
Many Tory MPs will feel Johnson’s time has past but his desire to run will not have faded and no-one would rule him out.
Bookies odds – 9/2
Former Brexit Secretary Davis is viewed by many Tory backbenchers as the ideal caretaker PM should May be toppled.
With an intimate knowledge of the negotiations and characters involved, leavers in the party would trust him to hammer out a new deal should the current draft be scrapped along with May.
The veteran Yorkshire MP lost out on his bid for the leadership in 2005, when David Cameron was running on a modernising ticket.
Davis was the first to resign when May announced her Chequers accord, somewhat beating Boris Johnson to the punch.
Davis has served in a series of top-level posts, including party chairman, Europe minister and chairman of the Public Accounts Committee.
Unlike Johnson and Gove, Davis’ campaign for Brexit was relatively low key and remainer Tories praised his attempts to build a consensus during negotiations.
Bookies odds – 10/1
Her return to the Cabinet as Work and Pensions Secretary on Friday - with responsibility for reforming the Government’s flagship benefit Universal Credit - could give Rudd a chance to redeem herself after the Windrush scandal forced her resignation. The new role could also be a poisoned chalice so bungled has its rollout been.
The one-nation Conservative is popular among remainers, and the Hastings and Rye MP’s may take the chance to stand but her slim majority (just 346 votes in it) and her stance on Breixt would work against her.
Rudd is very close to the PM, taking part in leadership debates on her behalf and had a speedy ascent to frontbench politics under David Cameron.
Bookies odds – 20/1
The Foreign Secretary is viewed as the remainers’ hope for the leadership.
As the longest-serving Health Secretary, he secured a £20bn funding settlement for the NHS, which has both won respect from moderates but enraged others who feel the health service gets too much Treasury cash.
An acolyte of David Cameron, Hunt made a bungled attempt to reach out to the Brexit wing of his party with his speech to conference in October when he compared the EU to the Soviet Union.
Despite raising the profile of the Foreign Office since Johnson’s departure, his full blooded support for remain in 2016 may be held against him.
Hunt has also served as minister for the Olympics and Culture Secretary.
Bookies odds – 8/1
The Outsiders ....
Jacob Rees-Mogg: The arch-Brexiteer chairs the powerful faction of Tory MPs, the European Research Group, but his socially conservative views - he opposes abortion and gay marriage - and his lack of experience in a ministerial role may rule him out.
Bookies odds – 14/1
Justine Greening: The former Education Secretary resigned rather than accept a move to oversee the implementation of the much-hated Universal Credit benefit. She has since been campaigning strongly on social mobility policy and votes at 16. Her vocal support for a so-called People’s Vote on the Brexit deal puts her in a minority. Given Brexit dominates, the contest may be too early a juncture for Greening.
Bookies odds – 50/1
Esther McVey: The Work and Pensions Secretary resigned after May published her draft Brexit deal but her closeness to the Universal Credit reforms would make MPs nervous of backing her.
Bookies odds – 66/1