Andy Burnham may be too Northern to appeal to the whole country, a leading ally admitted yesterday, putting a dent in his leadership ambitions.
Lucy Powell backed Mr Burnham's failed bid to return to parliament last month, but yesterday stopped short of publicly endorsing him to succeed Keir Starmer.
Ms Powell, Labour's deputy leader, said the public would see a lot more of the Greater Manchester mayor with Sir Keir in the coming weeks and months, despite his return to Westminster politics being blocked by the Prime Minister.
Ms Powell, who backed Mr Burnham's attempt to stand in a by-election later this month, praised his record as a champion of his city and the wider North.
But she said that the qualities he showed in the role might not translate as well if he was running the whole country.
Mr Burnham's application to stand in Gorton and Denton on February 26, which was rejected last month by Labour's National Executive Committee, was widely seen as a precursor to challenging Sir Keir for the Labour leadership and the keys to No 10.
Ms Powell, herself a Manchester MP, said on LBC radio that Sir Keir would end this week stronger than he started it, despite becoming embroiled in a major row over links between Labour figures and convicted paedophiles.
Discussing the ambitions of Mr Burnham she said she would support him 'in whatever he wants to do'.
Mr Burnham's application to stand in Gorton and Denton on February 26, which was rejected last month by Labour's National Executive Committee
Lucy Powell backed Mr Burnham's failed bid to return to parliament last month, but yesterday stopped short of publicly endorsing him to succeed Keir Starmer
But she went on to add: 'Being PM is a tough, tough job, every day things coming at you from around the world.
'[Burnham] is an asset to us, of course, he is an asset to us, and its a very different job.'
She added: 'He's running Greater Manchester and... what people do know in Greater Manchester or actually across the North, is that he is on their side and he stands up for our region.
Now that might be something that wouldn't translate so much when you are standing up for the whole country or whatever.'
Her intervention came as speculation continued to swirl around Sir Keir's leadership.
Ed Miliband admitted this week that the PM had faced a 'moment of peril' on Monday when Labour MPs and ministers 'looked over the precipice' of ditching him before eventually rallying round.
The wobble came after Scottish Labour leader Anas Sarwar called for the PM to quit after overseeing 'too many mistakes' in office.
Mr Sarwar yesterday stood by his comments, saying: 'I stated my view and I stand by that view because I am the one who is putting myself before the public in three months' time [in Scottish parliament elections on May 7] and the people in Scotland deserve to know what my standards are, what I believe, what I am willing to tolerate and what I would do differently if I was elected as first minister.'
Mr Carns, a former Special Forces officer, has told friends he is interested in being PM, despite only entering parliament in 2024
Wes Streeting was forced to deny fresh reports that he is plotting to oust Sir Keir in the coming weeks. Allies of the Health Secretary told the Guardian that 'nothing has changed' and that Mr Streeting had to 'act quickly'.
Mr Streeting denied the claims but is suspected of plotting by No 10. In a further sign of Labour chaos, Armed Forces minister Al Carns was forced to distance himself from an 'Al Carns for Leader' website, which was uncovered by the New Statesman magazine.
Mr Carns, a former Special Forces officer, has told friends he is interested in being PM, despite only entering parliament in 2024. But he said the website was not his and insisted Sir Keir had his 'full support'.
Former deputy PM Angela Rayner this week also denied a leadership website, that briefly went live in January, had been set up on her orders.
Meanwhile, a More in Common poll found that voters think Sir Keir should resign by a margin of 48:18. Even 42 per cent of Labour voters believe it would be good for the country if the PM stood down this year.
The poll found that 61 per cent of voters believe the PM has handled the Peter Mandelson scandal badly.