The latest YouGov survey shows support for Keir Starmer’s party has jumped by three points to 43% in the past week.
At the same time, the Conservatives have slumped by a point to just 20%, a massive 23 points behind their rivals.
Even more worryingly for Rishi Sunak, Reform UK are now just four points behind the Tories on 16%.
Meanwhile, a separate poll by Techne UK also showed Labour extending its lead over the Conservatives.
It put support for Labour on 45%, up one point on a week ago, with the Tories down a point to 22%.
The pollster said support for Reform UK has also increased by a point to 13%.
Both polls will further deepen the Tory gloom with the general election just a few months away.
They suggest that Sunak’s repeated attempts to boost his party’s fortunes, including tax cuts, new policies and multiple re-launches, have all flopped.
The polls also confirm separate surveys in recent days which suggest the Conservatives are heading for wipeout at the election.
A Survation survey for the Best for Britain campaign group last weekend said the Tories are on course to win fewer than 100 seats in what would be their worst ever result.
Another poll by YouGov showed Labour is set to win more than 400 seats, giving the party a 1997-style landslide victory.
The Tories, meanwhile, are on course to lose more than 200 seats, leaving them on just 155.