Nigel Farage warned the Tories have no idea “what is about to come down the track towards them”.
The former Ukip leader accused the party of betraying Brexit and being “so far away” from what most Conservative people believe.
He also rejected suggestions Reform UK should stand aside for Rishi Sunak’s party at the next general election.
Mr Farage was responding to a mega poll which suggested the Tories are on course for a 1997-style wipeout.
He told GB News: “I don’t think the Conservative Party have any idea what is about to come down the track towards them.
“And yes they thoroughly deserve it. They’ve lied to us, they’ve betrayed much of what Brexit was about, they have been truly, truly awful.
“I find this whole narrative that Reform mustn’t stand because the Conservatives might have a chance. You know they don’t have a God-given right to your vote.
“The Tories are so awful, they’re so far away from the centre ground of opinion of most Conservative people that actually the right thing would be for them to be replaced.”
Mr Farage’s comments come after a dire poll by YouGov of 14,000 people reported by The Telegraph.
It indicated that the Tories could be left with as few as 169 seats, as Sir Keir Starmer’s Labour enters Downing Street with 385.
The research, using the multi-level regression and post-stratification (MRP) method, was commissioned by a group of Tory donors working with former Brexit negotiator Lord Frost.
The MRP technique is a way of producing estimates of opinion and attitudes for small, defined geographic areas such as parliamentary constituencies.
But the Conservative elections guru Isaac Levido last night urged MPs at a meeting of the 1922 Committee to ignore the polling aimed at “undermining this Government”.
