A poll has seen the Conservatives push Reform UK down to the third place for the first time since January last year.
More in Common's latest survey found that 26 per cent of the electorate planned to vote for Labour, down one point in a sign that the so-called 'Burnham bounce' is already stalling.
Kemi Badenoch's Conservative party is in second on 23 per cent, up one point.
Reform UK is on 22 per cent, down one point, their lowest level of support in 18 months.
The Lib Dems meanwhile are on just 11 per cent, closely trailed by the Green Party on 9 per cent.
More in Common found Restore Britain, the hardline rivals to Reform UK founded by Rupert Lowe MP, on 4 per cent.
Sharing their findings, the pollster's UK director Luke Tryl caveated the surprise news with a warning that 'obviously these are margin of error changes, and we should expect things to fluctuate over conference season'.
He added: 'But this is the highest Conservative vote share since January of this year, and Reform's lowest in 18 months.'
More in Common found the Tories have now overtaken Reform UK, pushing Nigel Farage's party into third place
Kemi Badenoch's Conservatives are on the up, according to today's surprise poll findings
Nigel Farage's return to Parliament following his by-election victory was clouded today as Reform were pushed into third place
Meanwhile Labour were down one point, suggesting the 'Burnham bounce' is already waning
Mr Tryl added that the pollster has only been prompting Restore for two weeks, which will affect the vote share. 'Prompting' means Restore are included as a named option for those answering the poll, rather than relying on being manually submitted by the individual.
Reacting to the poll, a senior Tory source told the Mail: 'It’s still a long way to go, but it’s now clear Reform are going backwards.
'A pointless by-election vs a bin, chronic infighting, and still no answers on the fishy £5m personal donation; Farage is floundering and his party has now slipped to third in the polls.
'It’s surely only a matter of time before Farage decides to throw in the towel.'
There was further good news for Kemi Badenoch as More in Common found she is once again receiving net positive approval ratings for her leadership of the Conservative Party.
Ms Badenoch was up one point to +1 - though trailing Mr Burnham's 13 points.
Sir Ed Davey, the Lib Dem leader, was on -5, ahead of Rupert Lowe on -12.
However Nigel Farage is well behind on -27, just one point more popular than Green Party leader Zack Polanski.
Reacting to the poll, the Conservatives said: 'Under Kemi Badenoch's leadership, the Conservative Party is coming back.
'We are leading the way in holding Labour to account, and laying out serious plans for Government.
'We are the only party that will get Britain working again.'
It comes after Ms Badenoch conducted a sweeping reshuffle of her frontbench yesterday, as she prepares to get her party election-ready.
Ms Badenoch sacked her Shadow Chancellor, Sir Mel Stride, replacing him with the energetic Andrew Griffith.
Tom Tugendhat was appointed Shadow Foreign Secretary, replacing Dame Priti Patel.
A Conservative MP told the Daily Mail: 'Now is the time to move to a next phase of what a future Conservative Government would look like.
'Our new team will give us the energy we need to fight a general election.'