SIR KEIR Starmer said an Andy Burnham leadership challenge could plunge the country into chaos – as his rival opened the door to a major tax cut.

The Prime Minister sternly told the wannabe leader to back off insisting he won’t walk away from Downing Street.

Andy Burnham, Greater Manchester Mayor and Labour candidate, looking on.Greater Manchester Mayor and Labour candidate Andy Burnham Credit: Reuters British Prime Minister Sir Keir Starmer in Downing Street, holding a folder with the Royal Coat of Arms.Prime minister Sir Keir Starmer Credit: Alamy

His warning shot comes after the Greater Manchester mayor said he will join any leadership contest if he wins the Makerfield by-election.

Sir Keir said any battle would be a major distraction from the Middle East conflict and Russia’s invasion if Ukraine.

The PM said: “Andy has got a lot of talent, of course he has. We’re fighting hard in Makerfield.

“But I also profoundly believe that to plunge our country into the chaos of a leadership fight, when, as we’re talking about , we’re facing a war on two fronts.”

Prime Minister Sir Keir Starmer and Mayor of Greater Manchester Andy Burnham during a meeting.Prime MInister Sir Keir Starmer speaks to Greater Manchester Mayor Andy Burnham Credit: PA A man speaking into a microphone in front of a red backdrop with "PROGRESS" written repeatedly.Former Health Secretary Wes Streeting is the other leadership hopeful Credit: REUTERS

He told LBC Radio: “The Ukraine war is going on. We’ve got conflict in the Middle East. Both of these have to be resolved.

“We’re playing a leading part in that. We have to step up on defence and security of our country. These are serious issues for our time.”

The PM said voters expect him to get on with the governing after receiving a five-year mandate back at the 2024 – rather than an “internal fight” in the Labour party.

He said that will “distract us from the job that we’re elected to do”.

Mr Burnham last night opened the door to a national insurance tax cut – which could partially reverse a decision from Rachel Reeves’ first budget.

Employers furiously berated the government after the raid costs all firms £25 billion at the Budget in 2024.

When pushed on reversing the hike for small , he told BBC Newsnight: “Yeah, I’m sympathetic to that”.

He added: “I have said that I thought the weight of the burden on employers’ National Insurance wasn’t the right decision, however it was the decision.

“There is more that needs to be done to listen to the voice of small business and as I’ve gone around this constituency I’m hearing it a lot. People just feel they are at the kind of limits of what they can do.”

, Reform’s Treasury spokesman, said: “The self-proclaimed King of the North is offering crumbs off his table.

“This change wouldn’t even get close to undoing the harm Labour’s jobs tax has inflicted on businesses. Burnham seems to have already taken the voters of Makerfield for granted.”