The race to become the next leader of the Conservative Party, and consequently the next U.K. prime minister, has begun to accelerate with the first round of voting set to take place next week.
Whoever wins will have the unenviable task of trying to deliver Brexit after a political deadlock — and three failed parliamentary votes — helped bring down Theresa May who resigned as leader on Friday.
CNBC takes a look at the Conservative lawmakers who are vying for power through the prism of Britain's withdrawal from the EU.
This is not the first Conservative leadership contest for the former foreign secretary and mayor of London, after he prematurely ended a previous attempt in 2016 that paved the way for May to enter Downing Street.
He is one of Britain's most globally prominent but domestically-divisive politicians. May brought him into her government in a senior role that left him responsible for Britain's presence on the world stage and frequently kept him away from Westminster.
He later resigned from his post as a result of May's willingness to lead the U.K. into what he called a "semi-Brexit" that would leave Britain as a "colony" of the European Union.
He has recently insisted that Britain must stick to the new October 31 Brexit deadline; that he would attempt to renegotiate the complex and contentious Northern Irish backstop contained within the Britain's withdrawal agreement with Brussels — something May tried and failed to do repeatedly. But absent changes to that backstop, Johnson has said he would take the U.K. out of Europe without a deal.
The former minister tasked with handling Brexit negotiations for May after his predecessor David Davis resigned, Raab stayed in the role for a little more than four months before he too quit in protest at the deal May finally struck with the EU.
He called the deal a betrayal of Conservative Party manifesto promises made during the 2017 general election campaign, insisting that the Irish backstop was undemocratic and that the deal threatened the integrity of the United Kingdom because of regulatory differences it would introduce for Northern Ireland.
Raab is another leadership contender who says Britain must leave the EU on October 31, perhaps even without a deal, and he has hinted that it might be possible for a prime minister to pursue that course of action unilaterally, without parliamentary approval.
Her resignation as leader of the House of Commons made her the last of the three-dozen ministers who have stepped down from May's government in the past 13 months.
In a sign of the divisive nature of the Brexit process for those inside the British cabinet, she was the 31st minister to do so for reasons relating to the U.K.'s departure from the European Union.
In her role as Commons leader, Leadsom acted as the interface between the government and the lower chamber of the British parliament, a polarizing and at times difficult role during a period of heightened confrontation between the executive and legislature.
Leadsom's departure appears to have been the final straw for May's premiership, since it was within 48 hours that the embattled prime minister finally announced her Downing Street departure date. Leadsom had previously ceded her prime ministerial ambitions to May in 2016, to prevent a prolonged struggle between two final candidates in that most recent Conservative leadership race. But her raised public profile as a Leave campaigner during the Brexit referendum earlier that year had propelled her to the runner-up spot in that previous contest, despite her lack of cabinet-level experience.
The former work and pensions secretary under May, she resigned the same day as Dominic Raab and claimed that the prime minister's negotiated Brexit deal did not honor the result of the 2016 referendum.
In her resignation letter she repeated a common refrain among Conservative euroskeptics in recent months that the Northern Irish backstop contained in the withdrawal agreement would "trap" the U.K. in a permanent customs union with Europe, and would "bind the hands" of future governments that might seek to strike fresh trade deals.
Over the weekend, she told Sky News that what she called an "invisible border" between the Republic of Ireland and the United Kingdom is already technically possible, despite the EU's insistence that this is not yet the case. She argued that the U.K. must leave Europe on October 31, with or without a deal, and that politicians must regain the trust of the British public with an honest appraisal of the 2016 referendum result.
A former managing director at Deutsche Bank, Javid is the first member of an ethnic minority to serve as home secretary, the British equivalent to a minister of the interior with responsibility for immigration and security.
He took on the role after his predecessor resigned during a national scandal about their department's role in deporting legal residents whose residency paperwork the government had lost. In announcing his candidacy he said the dismal Conservative performance in the European parliamentary elections over the weekend showed that the party must deliver Brexit and do so quickly.
His personal backstory as the son of a bus driver is markedly different to that of many of his Conservative colleagues and competitors, but he too insists that restoring trust in British politics must be a priority. He originally voted to remain in the EU during 2016's referendum. This fact may work against Javid if he makes it through the parliamentary voting rounds to compete in a ballot of party members, since polls indicate that members' views on Brexit have become increasingly hardline and purist.
The minister responsible for Britain's health and social service system, he has previously worked as an economist at the Bank of England.
Hancock has written this week in British newspaper The Daily Mail that it is "mission critical" for the Conservative Party to complete the Brexit process, after its disastrous performance in European parliamentary elections.
He has tried to assure his fellow Conservative lawmakers that they would not need to go through a general election until after he has led them through Brexit as prime minister. But he has also made clear in a BBC radio interview that there must be "trade offs" between access to European markets and British sovereignty, in order to get a Brexit deal through the current parliament, he has indicated he would not be prepared to pursue a "no deal" policy.
One of the most high-profile Brexit supporters during the 2016 referendum, Gove's commitment to Brexit has never been in doubt, but he has also not insisted that October 31 must be a hard deadline for Britain to exit the EU.
He says he wants to unify his party and has implied that a deal with Brussels is ultimately the best way to do that. He damaged his reputation as a trustworthy politician for his decision to end his support for Boris Johnson during the last leadership contest in 2016, but even his political critics have acknowledged that he has proven himself a capable minister with innovative ideas. And according to one lawmaker who has campaigned for the rights of Europeans living in the U.K., Gove has promised this week that if he becomes prime minister then he will offer those roughly 3 million EU nationals the opportunity to obtain British citizenship free of charge.
The current foreign secretary has overnight reiterated in an article for British newspaper The Daily Telegraph his view that a "no deal" Brexit would be disastrous not only for the U.K., but would constitute "political suicide" for the Conservative Party as it would trigger a general election that would risk the party's "extinction."
Hunt has served in senior government roles for the best part of a decade, and oversaw Britain's hosting of the 2012 Olympics. He was a high-profile opponent of Brexit during the 2016 referendum campaign, but has publicly said he has reconciled himself with the need to honor the referendum result.
He replaced his Oxford University contemporary Boris Johnson as foreign secretary, and as the founder of a successful directory business before he entered government, he is the wealthiest member of the current cabinet. He has stated that his entrepreneurial acumen would help him renegotiate a better deal than May was able to reach with the EU.
As a relatively newly-installed international development secretary, Stewart perhaps enjoys a slightly lower profile outside of the U.K. than many of his rivals for the Conservative leadership. But he first rose to public prominence almost two decades ago when he wrote a book as a young British diplomat about walking solo across a war-torn Afghanistan just months after Al-Qaeda launched the 9/11 attacks from there.
He went on to administrate a southern Iraqi province after the 2003 U.S.-led invasion there, so he can lay claim to the rather unique experience of having mediated between warring tribes — a skill that might prove useful in contemporary Westminster.
He has said recently that British politics needs to take itself more seriously and has publicly criticized several of his competitors, most notably Boris Johnson. He says he wants to strike a deal and then to move on to focus on other domestic priorities if he becomes prime minister.
The minister currently responsible for housing, Malthouse gained a reputation as a pragmatist and mediator earlier this year when Conservative lawmakers with widely different views on Brexit came together for discussions he chaired, to thrash out a compromise that was then put to May.
It called for a reworking of the Irish backstop through the establishment of a free trade agreement between the U.K. and EU, as well as an extension to the Brexit deadline. But the suggestion — although voted through by Parliament — was never seriously pursued by May's negotiators, nor indeed European officials.
Malthouse was previously deputy mayor of London and voted for the U.K. to leave Europe, but in his announcement as a candidate he said that any deal will need "unity" across the country, and that a "new generation" of politicians unscarred by internal Conservative conflicts must lead the party forward into the future.