Who is Al Carns? The Scottish commando who conquered Everest looking to challenge Andy Burnham

However, there is one man potentially standing in his way - Al Carns MP.

At the beginning of the week, both Mr Carns and Chief Secretary to the Prime Minister Darren Jones were thought to be considering a bid to stand in any leadership contest to avoid a Burnham coronation.

However, Mr Jones has now said he will not stand and is endorsing Mr Burnham as Prime Minister.

Mr Carns has not yet made a statement on what he plans to do - but who is Mr Carns, the Scottish-born military man who could challenge Mr Burnham?

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The 45-year-old was born and raised in Aberdeen to a single mother and attended Hazlehead Academy.

He said this upbringing means he “knows what pressure does to families when money is tight and when the future feels uncertain”.

Mr Carns suffered various childhood accidents, including breaking his neck and his leg, and third degree burns to 11 per cent of his body.

Having initially been turned down from the military because of his colour blindness, he enlisted as a Royal Marine commando in 1999 aged 19.

Since then he has had a stellar 24-year military career, although much of it cannot be made public for national security reasons.

He served five tours of Afghanistan and in 2011 he won the Military Cross “in recognition of gallant and distinguished service”. Mr Carns also received a Distinguished Service Order and was given an OBE in the Queen’s birthday honours in 2022.

It has not all been plain sailing though - he estimates he has had four brushes with death, including being nearly dragged into the propeller of a ship during a mission in the Persian Gulf.

He is no stranger to a gruelling challenge. He went on an expedition to the Arctic earlier this year. Last year he climbed Mount Everest on an expedition with former special forces colleagues, and set a record by doing it in under five days by using xenon gas and hypoxic training to acclimatise.

But the question is now whether he can use those challenging experiences to conquer politics.

Mr Carns, who reached the rank of colonel, served as a military adviser to three defence secretaries before becoming an MP himself - Penny Mordaunt, Gavin Williamson and Michael Fallon.

He has also briefed US President Donald Trump on his visit to England during his first presidency.

It was expected that he would be promoted to brigadier before he resigned - if this had happened, he would have been the youngest to hold this position.

In 2024 he stood to be the MP for Selly Oaks in Birmingham and won the seat with a majority of 11,537. Just five days later, Sir Keir Starmer made him junior veterans minister.

Last year he became Armed Forces minister and re-enlisted in the Marines as a reservist.

He resigned from his government job earlier this month alongside Defence Secretary John Healey, saying he could not “in good conscience stand at the dispatch box and defend a level of investment I know to be inadequate to the task”.

Many see his and Mr Healey’s resignations as part of the catalyst for Sir Keir’s resignation on Monday. Many also see him as a potential leadership candidate because last month he published an article in The New Statesman called ‘How Labour can win again’.

This article set out a vision and mission statement for the party in the wake of Labour’s election drubbing, and insiders saw this as a sign of a leadership bid.

Last year he also approached the Scottish Labour MPs about becoming their candidate for Labour’s deputy leadership election, but the group decided the position had to be held by a woman.

The father-of-three is still weighing up whether or not to stand against Mr Burnham and force an election competition. However, despite having a stacked CV when it comes to defence, he is untested on other areas of government.

He could be holding out to try and get some promises on defence spending from Mr Burnham. Mr Jones only agreed to not stand after getting reassurances on economic policy - perhaps Mr Carns could do the same.