Theresa May’s announcement to Conservative MPs that she is prepared to step down should her EU withdrawal deal pass has sparked speculation about who might take over the reigns.
It comes after months of speculation over her position, with the PM facing pressure from all sides of her party and the House of Commons to stand down.
The Prime Minister’s told the 1922 Committee she "won’t stand in the way" of new leadership in the second phase of Brexit negotiations.
Although no date has been set for her departure bookmakers, leadership hopefuls could be set to position themselves to take over at Number 10.
Here's a shortlist of some of the Tory leadership hopefuls who could throw their hat in the ring to take the helm if Mrs May steps down.
The Environment Secretary had a bruising experience in the last Tory leadership race but he is now seen as the favourite to replace Mrs May, largely due to his Brexiteer credentials.
In June 2016, Mr Gove, who was campaign manager for Boris Johnson’s drive to succeed David Cameron, withdrew his support on the morning Mr Johnson was due to declare and threw his own hat in the ring instead.
The Brexiter could win over support from grassroots Conservative party members, who would have the final say on any possible leader.
He came third in the first round of voting, trailing behind ultimate winner Mrs May and Andrea Leadsom.
Mr Gove, 51, was born in Edinburgh, studied English at Oxford and was a journalist before becoming an MP.
Despite speculation he could take the job, he told reporters on Sunday it was "not the time to change the captain of the ship".
Mrs May’s de facto deputy is seen by some as the natural caretaker prime minister but he has been clear he does not want the job.
"One thing that working closely with the Prime Minister does is cure you completely of any lingering shred of ambition to want to do that task," he said on Sunday.
The 62-year-old has been the MP for Aylesbury since 1992 and was minister of state for Europe from 2010 to 2016.
Prominent Brexiteer and former foreign secretary Mr Johnson has been 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 Mr Cameron but ruled himself out of the 2016 leadership contest after Mr Gove made a last-minute bid for the top job.
Foreign Secretary Jeremy Hunt was a prominent Remainer in the 2016 referendum.
As health secretary, Mr Hunt fought a long battle with doctors over a new contract.
The 52-year-old, who was first elected as MP for South West Surrey in 2005, was appointed Foreign Secretary in July following the resignation of Mr Johnson.
He chose not to run in the 2016 leadership contest and instead gave his full support to Mrs May, saying it was "not the right time" to put his hat in the ring.
Mr Hunt made a public shift towards Euroscepticism after the referendum, which could win him allies in the Leave camp if he ran for the top job.
The former Brexit secretary is an outlier to take over from the Prime Minister but is thought to harbour ambitions for the role.
Mr Raab, a prominent Brexiteer in the referendum campaign, was appointed as Brexit secretary in July but resigned from the role in November, saying he could not support Mrs May’s eventual deal.
In his resignation letter on November 15, he wrote: "Ultimately, you deserve a Brexit Secretary who can make the case for the deal you are pursuing with conviction. I am only sorry, in good conscience, that I cannot."
Mr Raab, 44, has been the MP for Esher and Walton since he was elected in 2010.
In a magazine interview in December, Mr Javid sought to signal his leadership ambitions by arguing that he wanted the Tories to be the party of social mobility.
Javid, 49, backed Remain in the referendum but has since positioned himself as a firm Leaver.
He became the first home secretary from an ethnic minority background when he was appointed in April 2018.
The son of a Pakistani bus driver from Rochdale, he was a managing director at Deutsche Bank before becoming MP from Bromsgrove in 2010.
Secretary of State for International Development Penny Mordaunt is one of the Cabinet’s most prominent Brexiteers.
She pledged her support for Andrea Leadsom in the 2016 Conservative leadership contest.
Ms Mordaunt, 46, has been an MP for Portsmouth North since 2010 and is a Royal Navy reservist.
In 2014, she appeared on reality TV show Splash!
David Davis plunged the Government into crisis after he resigned from the Cabinet in July last year over the Chequers deal, followed out the door by fellow Department for Exiting the EU minister Steve Baker.
The long-term Leaver was a candidate for leadership in 2001, when he came fourth, and in 2005, when he came second to the former Prime Minister David Cameron.
A former SAS reservist, Mr Davis, 70, has been the MP for Haltemprice and Howden since 1997.
Amber Rudd made a return to the Cabinet as Secretary of State for Work and Pensions in November after her resignation as Home Secretary earlier this year following the Windrush scandal.
The Remainer has said she wouldn’t rule out a second referendum but has openly favoured a Norway Plus model, which involves staying in the European Economic Area.
Ms Rudd, 55, became MP for Hastings and Rye in 2010.
Leader of the Commons since June, Andrea Leadsom found herself at the centre of controversy in the 2016 leadership campaign when comments she made were interpreted as a claim that she would be a better PM than Mrs May because she was a mother.
She has previously refused to rule out another leadership bid in the future.
Mrs Leadsom, 55, has been the MP for South Northamptonshire since 2010 and has held a number of Cabinet roles.