A 2024 election wipe-out is a "risk" the Tories now face with it being "extremely difficult" for them to win the next election, a polling guru has said.
Professor Sir John Curtice said Sir Keir Starmer's Labour Party are now "favourites" to win with a "half decent chance" of an overall Commons majority.
He said the Tories have lost ground "across the whole of the electorate" due to the public in general deciding they "cannot be trusted to run the country".
Sir John noted that there has been "some recovery" since Rishi Sunak, who is personally more popular than his party, became Prime Minister last week.
But he warned voters were unlikely to forgive the Tories for the crisis which his predecessor Liz Truss unleashed.
He said that at the height of Ms Truss's unpopularity, the Conservatives had been trailing Labour by more than 30 points in the polls suggesting they could have been left with fewer than 60 seats if that pattern had been repeated at a general election.
Asked whether the Tories can win the next election, he told reporters on Wednesday: "History suggests that it's going to be extremely difficult.
"No government that has presided over a fiscal or financial crisis has eventually survived at the ballot box... 1948, 1967, 1976, 1992, 2008. It's not a happy litany of precedence.
"It's going to be very, very difficult."
He added that much will depend on the economy in the next two years but warned the "odds are against" Mr Sunak in turning around the party's fortunes.
"It's pretty clear at the moment - two years out - the Labour Party are the favourites to win the next election and that for the first time in this Parliament it looks as though they've got a half decent chance of getting an overall majority. That is a fundamental change."
Pressed on whether the Conservatives are heading for a historic defeat on the scale of Tony Blair's landslide in 1997, Sir John said: "It's two years to go - lots of water under the bridge.
"It is clearly now a risk that the Conservative Party faces," he added.
"I think you wouldn't find many Conservative MPs who would not accept that's a risk the party now faces."
However, he warned: "Blair for good or ill was a lot more popular than Starmer currently is or ever has been. There is still that sense among the public that they are not quite sure what the Labour Party stands for."
Assessing the collapse in the Conservatives' fortunes, he also warned that the damage of the Partygate scandal is "still with us" - despite Boris Johnson's downfall.
He also said that support for rejoining the EU has been growing steadily over the past year with the latest polling suggesting 57% would favour rejoining with 43% against.
