Labour's civil war raged on to a new front today as  Sadiq Khan condemned Andy Burnham-backed plans for a 'Northern' Olympics.

The London Mayor hit out at the prospect of snubbing the capital from a bid to host the global event in the 2040s.

Ministers have commissioned UK Sport to conduct an 'initial strategic assessment' into whether the North could stage the Games.

The funding agency is working to assess the possible costs and benefits, and whether a proposal would have any chance of success.

Culture Secretary Lisa Nandy said the Government was 'starting the firing gun'.

But Sir Sadiq branded the idea a 'missed opportunity', suggesting that without London the bid would be doomed.

The spat came as Labour clashes escalated over Mr Burnham's push to seize the leadership.

The Manchester Mayor wants to fight a high-stakes Commons by-election in Makerfield, which would put him in pole position to take over from Keir Starmer.

But Mr Burnham's allies lashed out today after leadership contender Wes Streeting voiced support for rejoining the EU.

That highlighted Mr Burnham's own strident views on reversing Brexit – seen as deeply unhelpful when he is wrestling Reform in the Eurosceptic seat.

Even fans of Mr Burnham say his chances of success could be worse than 50-50, with polls having consistently shown Nigel Farage's outfit on track to win.

Sir Keir visited Labour HQ this morning to thank staff for their hard work, insisting he would 'get on with the job'. He pledged to support whatever candidate is fighting Reform at the by-election.  

Deputy PM David Lammy acknowledged that the 'internecine warfare' after disastrous local elections was a 'spectacular own goal'. 

'Some colleagues are lighting the match and standing in the petrol,' he warned, hinting that a general election could be inevitable if the party does not pull together.

But Mr Lammy refused five times to say whether he personally wanted to rejoin the EU.

The Labour meltdown has exposed the growing North-South divide within the party. 

A spokesman for Sir Sadiq said of the Olympics bid: 'London is the sporting capital of the world and the Mayor has openly expressed his ambition for the capital to be part of a future Olympic and Paralympic Games.

'Sadiq believes that a potential country-wide bid, using all the assets we have in the UK, including the publicly-owned London Stadium would deliver the very best possible Olympics.

'Using London's existing world-class infrastructure would help deliver the greenest and most sustainable Games, as well as unlocking huge economic growth both here in London and around the country.

'Not including the capital in an Olympics bid would be a missed opportunity, and mean our country fails to unleash the full benefits of a UK-wide games.'

Making the case for a northern bid yesterday, Ms Nandy said: 'For too long we have been told the Olympics is simply too big and too important to be hosted in the north.

'Not any more. It's time the Olympics came north and we showed what we can offer to the world.

'We know that we can pull off the most incredible, not just bid, but Olympics. So we're kick-starting that with a phase-one study about the investment, the resources, the infrastructure, the transport that we're going to need.'

Mr Burnham said in February: “Hosting the Olympic and Paralympic Games would be a defining moment for the North and we are confident our bid would make for a compelling proposition. 

'Much of the infrastructure is already in place, our facilities are second-to-none, and we have a track record of hosting major global events.' 

The findings of UK Sport's ongoing assessment will determine whether to proceed with the next stage of preparing a bid.

This would mean putting together a 'technical feasibility study', but the final decision on any bid would remain with the British Olympic Association (BOA).