Who will replace David Cameron? Winner will spearhead Brexit.

After nominations close at noon Thursday, Conservative lawmakers will vote and whittle the nominees down to two

British Prime Minister David Cameron turns to walk away as he finishes making a statement appealing for people to vote to remain in the European Union outside 10 Downing Street in London, Tuesday, June 21, 2016. Britain votes whether to stay in the EU in a referendum on Thursday. (AP Photo/Matt Dunham)

British Prime Minister David Cameron June 21, 2016.  (AP Photo/Matt Dunham)

LONDON — Britain has not yet quit the European Union, but it has already left politics-as-usual far behind.

Conservative Party contenders began to emerge Wednesday to replace Prime Minister David Cameron in the wake of Britain’s vote to leave the bloc, while the head of the opposition Labour Party tried to cling to power in the face of a growing rebellion in party ranks.

Cameron announced his resignation after British voters decided last week, against his advice, that the U.K. should leave the 28-nation EU. His successor will get the challenge — or the poisoned chalice — of becoming the country’s next leader and negotiating Britain’s exit.

The first contender to make it official was Work and Pensions Secretary Stephen Crabb, who said he was running because “I don’t see anybody who provides a compelling answer” to the question of how to heal a deeply divided nation.

The 43-year-old Crabb, raised by a single mother in public housing, said he would offer “resilience, optimism, humility, strength.” Although he backed the “remain” side in the referendum, he promised to deliver a “negotiated exit” from the EU.

Crabb is running with Business Secretary Sajid Javid — who would serve as his finance minister — on what has been dubbed a blue-collar ticket. Both men come from working-class backgrounds, in contrast to upper-crust front-runner Boris Johnson, the former mayor of London, and the current prime minister, Cameron.

Johnson, who led the “leave” side in the referendum, has the support of several senior Tory lawmakers. Environment Secretary Liz Truss wrote in the Daily Telegraph that she was backing the 52-year-old Johnson because the new leader must be “someone who believes in, and campaigned for, leaving the EU.”

Home Secretary Theresa May, who backed the “remain” side but is seen as competent and experienced, is also expected to run.

May, 59, could appeal to a large chunk of Conservatives who mistrust the flamboyant, Latin-spouting Johnson, who has been accused of using the referendum as a platform for his leadership ambitions and of failing to draw up plans if his “leave” side did win.

Tory lawmaker Alan Duncan compared Johnson to the erratic former Italian Prime Minister Silvio Berlusconi, dubbing him “Silvio Borisconi.”

After nominations close at noon Thursday, Conservative lawmakers will vote and whittle down the candidates to two. Those names will be put to a postal vote of all party members, with the result expected in early September.

The opposition Labour Party is also in turmoil at the top, with leader Jeremy Corbyn resisting intense pressure to resign.

Labour members of Parliament passed a no-confidence vote on Corbyn by 172-40 on Tuesday — but Corbyn says he has the support of grass-roots party members and will not resign.

Many Labour supporters accuse Corbyn of failing to make a strong case for remaining in the EU during the referendum campaign.

A chorus of anti-Corbyn statements poured out Wednesday from Labour lawmakers fearful that their party will be wiped out if the new Conservative leader calls a quick election while the staunchly socialist, doggedly uncharismatic Corbyn is at the helm.

Corbyn’s predecessor, Ed Miliband, said Britain was facing its biggest crisis since World War II and “Jeremy cannot rise to that challenge.”

Ex-Labour Cabinet minister Tessa Jowell declared the party was in “a complete shambles,” while a former interim leader of the party, Harriet Harman, said Corbyn had failed “and he has no right or mandate to stay in office despite his failure and take the party down with him.”

The imminent departure of Cameron and the rebellion against Corbyn gave a surreal tone Wednesday to the normally raucous Prime Minister’s Questions session in the House of Commons.

Labour Party lawmakers declined to cheer Corbyn and sat in stony silence as he quizzed Cameron on the economic implications of a British exit _ or Brexit. Cameron, for his part, said it was not in the national interest for Corbyn to keep his job.

“For heaven’s sake man, go!” Cameron urged the Labour leader.

Looking for more?

Get the Best of Maclean's sent straight to your inbox. Sign up for news, commentary and analysis.