The Tories are on course to win fewer than 100 seats at the next election, according to a new mega-poll.

The Survation survey for the Best for Britain campaign group says Labour is set to win a landslide 142-seat majority on a catastrophic night for Rishi Sunak.

The poll of 15,000 people puts Labour on 45% overall, with the Conservatives on 26%, the Lib Dems on 10% and Reform UK on 8.5%.

But a seat-by-seat analysis of the findings leaves Labour with 468 MPs, the Tories on 98, the SNP on 41 and the Lib Dems on 22.

Cabinet big-hitters Penny Mordaunt, James Cleverly and Grant Shapps are among the high-profile Conservatives who would lose their seats if the poll is correct.

Even Sunak himself, along with Claire Coutinho, Michelle Donelan, Oliver Dowden and Michael Gove, are at risk as the Tories face total meltdown.

The party would also be left with no MPs in Scotland or Wales, according to the poll.

Although the poll predicts Reform UK will not win any seats, the right-wing party is set to take support from the Tories in seats across the country.

Naomi Smith, chief executive of Best for Britain, said: “With the polling showing swathes of voters turning their backs on the Tories, it’s clear that this will be a change election.”

The findings will pile yet more pressure on the prime minister amid mounting speculation that he could be ousted by Tory MPs even before the election takes place.

Polling experts have predicted the party will lose 500 seats at the local elections on May 2, a result which could trigger a wave of no confidence letters being sent in to Sir Graham Brady, chair of the 1922 Committee of Tory backbenchers.

It has been suggested that Sunak could call an election for June or July in an attempt to see off any challenges to his leadership.