The Conservatives are facing an unprecedented “wipeout” in this week’s European elections and could end up with “zero” seats, one of the party’s most senior MEPs has predicted.

After polls closed on Thursday Daniel Hannan, a leading Brexiteer who once led the Tories group in the European Parliament, said his party would pay a price for its failure to deliver Brexit.

“Thank you to everyone who voted for the Conservatives today. My sense, for what it’s worth, is that we are facing a total wipeout – zero MEPs. I just hope our next leader can get Brexit over the line,” he said.

Polls certainly suggest the Tories are heading for their worst national election result in history, and could on a very bad night even be reduced to a vote share of single figures.

Though votes were cast in the UK on Thursday, the final results will not be released until after 10pm on Sunday night, when polls have closed in all 28 EU member states.

The current record low result for the Tories was the previous 2014 EU elections, in which they won just 23.1 per cent.

Most of the Tories' voters are expected to go to the Brexit Party, Nigel Farge's new outfit – which looks set to romp to victory.

The backdrop to the historically poor result is Theresa May's failure to get her Brexit deal through parliament, despite three, going on four, attempts to do so – which included government defeats of historic proportions.

On the eve of the election Conservatives Cabinet ministers rubbed salt into the party's wounds by reportedly launching an attempted coup against the prime minister's party leadership – just hours before voters headed to polling stations.

Ms May is expected to confirm her resignation on Friday, with a successor expected to be put in place by early June.

The runaway frontrunner to replace her is Boris Johnson – who has suggested he might take Britain out of the EU without a deal. Other cabinet ministers are also thought to want the job, however, in what could become a fierce leadership contest.

Britain is set to leave the EU on 31 October 2019 if it does not get another extension to the Article 50 negotiating period.