Britain is heading to the polls in an election that was not supposed to happen - and the two main parties are expected to face a drubbing as a result.
The Tories and Labour parties are predicted to suffer severe losses in the European Parliamentary elections, with the Brexit Party and Lib Dems predicted to hoover up the deserting voters.
Theresa May is already under intense pressure to resign and the predicted losses the Tories face in the polls will only add to her woes - and give her little choice but to leave Downing Street.
Latest polling from YouGov put Nigel Farage’s Brexit Party on 37% - nearly double the second placed Lib Dems (19%).
Labour are sitting in third place on 13%, while the Tories are languishing in fifth place, with 7% of the vote - putting them behind the Greens on 12%.
Mrs May had hoped cross-party Brexit talks would deliver a compromise deal in time to allow her to call off the European Parliament elections.
But the talks broke down without conclusion and her last-gasp effort to persuade MPs to back her deal backfired spectacularly.
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Foreign Secretary Jeremy Hunt has suggested that Mrs May will cling on to power until after the results are in on Monday.
In response to a question about whether Mrs May will still be PM when Donald Trump visits the UK in June, Mr Hunt said: “Theresa May will be Prime Minister to welcome him and rightly so.”
However she could still resign before then and remain in post while a leadership battle takes place over the summer.
Mrs May’s key Brexit legislation has also been pulled from the Commons schedule, prompting speculation the Prime Minister is on the verge of quitting.
Downing Street had insisted the second reading of the Withdrawal Agreement Bill (WAB) would go before MPs in the week beginning June 3, but it was not announced when the Government set out the forthcoming Commons agenda on Thursday.
On Wednesday, Downing Street had said the WAB would be published on Friday and debated by MPs in the first week of June.
But Government whip Mark Spencer, outlining forthcoming business in the Commons on Thursday, said: "We will update the House on the publication and introduction of the Withdrawal Agreement Bill on our return from the Whitsun recess."
However, it is not clear whether the bill was pulled because Mrs May is about to quit - or whether she intends changing it following reaction from Tories.
Downing Street conceded on Wednesday that they expected a "very challenging night" when the Euro results come through.
A spokesman said: "The PM is focused on the task at hand which is delivering the Brexit people voted for.”
Labour leader Jeremy Corbyn said voting for Labour represented a vote for a "tolerant and fairer country", and an "end to the division and austerity which has devastated our communities for a decade”.
He said: "We will continue to oppose the Tories' bad deal or a disastrous No Deal. If we can't get an agreement along the lines of our alternative plan, we will take it back to the people whether it's through a public vote or General Election.
"A vote for Labour is a vote for the only party that stands for the real change our country desperately needs, to benefit all communities, not just a privileged few.”
When Britain does finally leave the EU, the European Parliament will reduce from 751 MEPs to 705, with 27 of the UK's 73 seats being distributed among the remaining member states.
Results of who has been elected as the new MEPs will not be announced until Sunday evening when the last polling station on the continent closes.
England is split into nine regions: South East England has 10 MEPs, London and North West England each have eight, East of England and the West Midlands each have seven, Yorkshire and the Humber and South West England have six each, the East Midlands has five and North East England has three.
Scotland has six MEPs, Wales four and Northern Ireland three.