Andy Burnham faces questions over his flip-flopping on Brexit, tax and immigration today as he formally launches his by-election campaign.

The Greater Manchester Mayor will attempt to gain momentum as his high-stakes battle for the Makerfield constituency ramps up.

Polls have consistently shown that Reform is poised to take the seat. But Mr Burnham is hoping that his local 'star power' can overcome the wider trend, after one of his allies dramatically quit to hand him a route back to the Commons.

As the sun blazes over Manchester, scrutiny is heating up over Mr Burnham's policy positions - which he vaguely terms 'Manchesterism'. 

That could soon be Labour's platform if he can triumph on June 18 and take the keys to No10 from Keir Starmer. 

The former minister under Tony Blair and Gordon Brown has been pitching to Labour's Left. 

But he has already backed off his pledge to rejoin the EU - a view popular among MPs but regarded as deeply unhelpful in an area that heavily endorsed Brexit.

Allies have been suggesting that Mr Burnham will stick to Chancellor Rachel Reeves' fiscal rules, after markets took fright at his previous hints they could be torn up to allow more borrowing and spending.

He is also believed to have told Home Secretary Shabana Mahmood he supports her tough immigration crackdown. He told the Manchester Evening News today that a 'stronger grip' is needed on the UK's borders. 

Critics have accused him of watering down his commitment to a proportional representation - PR - voting system. 

Instead Mr Burnham has suggested he would like MPs to be elected using the supplementary vote method, and kicked the issue down the road by admitting it would need to be in a manifesto first.

Other policies floated by the mayor in the past include increasing the top rate of tax to 50p, while he has praised Gordon Brown's disastrous 10p tax rate. 

He has also suggested that 'wealth' would be shifted from the South to the North of England.

In his MEN interview this morning, Mr Burnham insisted he did not want mass nationalisations.

'I've talked about public control rather than nationalisation,' he said.

'I'm not saying nationalisation is wrong, it can be right in many contexts, rail being a really good example. But when it comes to things like energy, I think it's better to think of a more localised, regionalised approach to it.

'In London I think there's a case for public ownership of Thames Water. But it will vary and you've got to make it affordable. So it's not about just nationalising everything at a stroke.'

The lack of definition of the mayor's approach has come to the fore as the Makerfield by-election ramps up.

Josh Simons, the Labour MP who stood down to make way for Mr Burnham, won in 2024 by just 5,399 votes while Reform comfortably won every ward in the constituency at this month's local elections.

Sir Keir said yesterday he would be campaigning in Makerfield.

He said: 'Yes, and I've said to the whole Labour movement that I want everybody to be involved in the campaign, whatever other discussions are going on, it's really important – that's a straight fight between Labour and Reform.'

However, it is not clear that will be good news for Mr Burnham, given the PM's dire popularity ratings. 

A spokesman for the mayor said: 'Anyone who wants to embrace Andy's campaign message is welcome on the campaign.'

Mr Burnham will take on Reform UK's Robert Kenyon, a local plumber who contested the seat for the party in 2024.

The Green Party meanwhile has reopened nominations for its candidate after Chris Kennedy dropped out some nine hours after being announced to be running for the party.