A Labour government led by Andy Burnham could beat Nigel Farage's Reform UK at a general election, a new poll has suggested.

The bombshell survey has led to renewed calls to 'unite the Right' to stop the Mayor of Greater Manchester's return to Westminster - and a potential future Left-wing coalition.

The poll found that Labour would get an eight-point boost if Mr Burnham is successful at the Makerfield by-election next month and challenges Sir Keir Starmer in a leadership battle.

The More in Common survey suggests that Labour would secure 30 per cent of the vote under Mr Burnham compared to Reform's 27 per cent if an election was held tomorrow.

The Conservatives would trail behind both parties on 20 per cent, the Liberal Democrats on 11 per cent and Zack Polanski's Green Party would secure 7 per cent of the vote.

The findings will encourage backers of the leftwing Mayor but will send shockwaves through the Tories and Reform as it suggests a split Right-wing vote could allow Labour to keep hold of power.

It will also renew calls to 'unite the Right' to stop a 'rainbow coalition' of Labour, the Greens and Lib Dems after Mr Polanski said Mr Burnham was somebody he could work with to stop Reform.

Several Tory MPs have already called for a pact with Mr Farage's party at the Makerfield by-election to prevent the Right-wing vote from being split and offering Mr Burnham a route through the middle.

On Wednesday former business secretary Sir Jacob Rees-Mogg said the poll gave renewed impetus to the need for a unified Right.

He said: 'Failing to do a deal with Reform would give Labour a tremendous, if probably short lived boost.

'It cannot be in the national interest to help the political opportunism of the socialist weathervane Andy Burnham, who would be economically even worse than Reeves.'

Both parties have so far resisted calls for a pact. On Tuesday Reform announced local plumber Robert Kenyon as their Makerfield candidate while the Greens were expected to select theirs on Wednesday night. 

The Conservatives on Wednesday announced local former councillor Michael Winstanley as their candidate for the Makerfield by-election. Mr Winstanley, who grew up above his parents’ corner shop in the area, stood for the Tories in the constituency at the 1997 general election when he finished second behind Labour with 6,942 votes.

The survey of 2,599 Britons found that as Labour leader, Mr Burnham would win back a third of voters who have ditched the party since the 2024 general election.

Nearly half of defectors to the Greens or Lib Dems would return to Labour, as well as a fifth of those who have moved rightwards to Reform or the Tories, it adds.

More in Common UK director Luke Tryl said: 'This is one of the most high-stakes by-elections in history, and the future trajectory of the Labour Party, and indeed British politics more broadly, may depend on what happens in the next month.'

He added: 'People recognise the mayorality and premiership are different roles and a large part of Burnham's appeal rests on championing the north and fighting Westminster - if he is successful in Makerfield, it could be challenging to sustain his reputation as an outsider from within the House of Commons, especially during this era of anti-politics.'

Mr Burnham has been confirmed as Labour's candidate in the Makerfield by-election - which will take place on 18 June - after it was triggered by his ally quitting to open up a path to the Commons.

In order to have a tilt at the leadership, Mr Burnham must first win the seat. Labour won Makerfield at the 2024 election with a majority of 5,399 over Reform, while the Conservatives came third with 4,379 votes - meaning the majority would be virtually wiped out if the Tories stood aside.