Theresa May's removal as British Prime Minister could begin as early as Friday after the "last chance" version of her Brexit deal fell flat on all sides of the House of Commons.
One of her most senior cabinet ministers, Andrea Leadsom, resigned in protest and will campaign to replace her.
And with her Conservative party widely expected to be punished in the European elections, key members will meet on Friday — after British polls have closed — to consider bringing forward a leadership contest.
May promised to announce a timetable for her departure once Parliament has voted on her deal, but it looks increasingly unlikely she can hang on that long. She could even be gone before US President Donald Trump makes a state visit on June 4.
As British voters were making their choices on Thursday, the Pound Sterling took a battering on the currency markets amid fears May's replacement would come from her party's powerful anti-EU wing, such as former foreign secretary and no-deal advocate Boris Johnson.
But some analysts are not convinced that even a bulldog figure such as Johnson could force a no-deal Brexit before the current withdrawal deadline of October 31.
What does Brussels think?
At the EU Commission daily news briefing on Thursday, Euronews' Bryan Carter asked the spokesman if a new British PM would increase the likelihood of a no-deal.
Margaritis Schinas replied only that Brexit was not "on our mind".
"We are geared to a positive agenda of the European Union and that's what matters to us. We will always be ready to speak to the prime minister of the United Kingdom," he added, reiterating that Britain's withdrawal deal would not be changed.
Much hangs on the results of Britain's European elections. While polls close on Thursday, the outcome won't be known until after the rest of the EU has voted on Sunday evening.
It will then be clear how many frustrated pro-Brexit voters have abandoned May's Conservatives in favour of Nigel Farage's Brexit Party.
"If you want Brexit, you've got to vote Brexit. We did it once. They ignored us. So we're going to tell them again," Farage said on Thursday as he voted.
But it will also be known how many pro-remain voters have deserted the main parties in favour of those promising to abandon Brexit, such as the Liberal Democrats, Greens or Change UK. That could make the case for May to be replaced by a more moderate figure in favour of a re-packaged deal.
No-deal by default on October 31
Professor Sara Hobolt of the London School of Economics said no-deal remained the legal default outcome on October 31.
“While a majority in Parliament may not favour a no-deal outcome, it could still happen unless Parliament can agree on the working agreement or revoking Brexit or a new government that could request an extension from the EU.
“There are many paths that lead to a no-deal outcome, but fewer that prevent it, in my view," she added.
Maddy Thimont Jack of the Institute for Government believes a new government could not be formed in time to seek yet another extension. MPs “no longer have a decisive route to prevent a no-deal Brexit,” she said.
But John Curtice, an election expert and professor of politics at Strathclyde University, told an audience at the Social Market Foundation think tank that he believes there is “little chance” of no deal because MPs would collapse any government that forced it through.
“In effect, any PM who pushed for no-deal would see their government collapse in the autumn and risk a general election where there would be a significant chance that Labour would end up in government before the end of the year,” he said.
May’s own Chancellor of the Exchequer, Philip Hammond, made a speech on Tuesday warning that a no-deal scenario was looming.
"There is a real risk of a new prime minister abandoning the search for a deal and shifting towards seeking a damaging no deal exit as a matter of policy in order to protect an ideological position which ignores the reality of Britain's economic interests and the value of our precious union,” he said.
It is a fear shared by analysts including Karen Ward, chief market strategist for EMEA at JPMorgan Asset Management, who said markets were reflecting “a higher risk of no deal or a change of government.”
Robert Halver, of Germany’s Baader Bank, said May’s departure would put Brexit “back at the beginning again.”
“She has achieved nothing and what's terrible is, that this will kill any kind of Brexit deal. There is a big danger now, also in light of the expected poor EU election result for the British Conservatives, that hardliners will have the say which increases the risk of a no-deal Brexit.