A leading figure at the body set up to promote the Northern Powerhouse concept has criticised the lack of commitment from the current government to devolution as a "frustration" for local leaders.
Henri Murison, director of the Northern Powerhouse Partnership chaired by former Chancellor George Osborne, said the way powers and resources are being handed to the regions from Whitehall "might not necessarily be fit for purpose".
Speaking today in front of the Commons Business, Energy and Industrial Strategy Committee led by Leeds MP Rachel Reeves, Mr Murison said Prime Minister Theresa May had never been to visit the North's metro mayors.
He said: "What we need to see from the next Prime Minister is a real commitment to devolution."
Speaking at the same evidence session, James Farrar, Chief Operating Officer of the York, North Yorkshire and East Riding Local Enterprise Partnership, called on progress to be made quickly on One Yorkshire devolution after months of deadlock.
Mr Murison, a former senior Labour councillor in Newcastle, said the Northern Powerhouse concept had made an impact but that progress had been patchy on industrial policy, with the Government's national energy policy holding the North back.
He said: "There is a lot more detail that needs to be put on this agenda for it to genuinely address the scale of ambition that George Osborne set up as Chancellor.
Referencing the Power Up The North campaign led by The Yorkshire Post he said: “The lack of momentum that happened when the current Prime Minister first took office has been somewhat addressed. But we need to go further which is why people like our regional newspapers have been campaigning for more progress.”
He said the different speeds at which devolution had been introduced in the North had led to "some inequities and this does cause tension", highlighting the difference in powers between Greater Manchester and the Leeds City Region, which has yet to benefit from devolution.
He said: "In a Parliament with limited ability to change legislation we have concerns that the model of devolution might not necessarily be fit for purpose for the areas that haven't taken advantage of it."
Saying that "I sometimes despair" over the Government's approach to the issue, he said: "Across the Cabinet there has been a lack of incentive to move on devolution, [there is] no devolution framework yet.
"That has been a frustration for a lot of people in the North of England who have wanted to embrace the current movement but because of the lack of commitment from the cabinet have been unable to make progress and I think that is a frustration."
He added: "What we need to see from the next Prime Minister is a real commitment to devolution. There is a lot of talk about northern transport issues but if you don't have an answer to education and skills, and skills can only be done at the level of functioning economic geographies, you are not going to make progress on re-balancing the economy.
"You are just going to take the limited number of people with high skills to the bigger cities and create bigger skills disparities in the areas that are more marginal."
Asked who in the Cabinet had been supportive of the Northern Powerhouse, Mr Murison mentioned Transport Secretary Chris Grayling and Chancellor Philip Hammond. He said unlike the Chancellor, Prime Minister Theresa May had never been to meet with the North's metro mayors.
He said: "Either you have, as The Yorkshire Post has argued, a Cabinet Minister with a specific responsibility for the Northern Powerhouse, or you have a Prime Minister who takes a much more active interest in this agenda."
Committee member and Derbyshire Dales MP Sir Patrick McLoughlin, a former Transport Secretary, said: "When I was in the Cabinet George Osborne was driving it and driving it incredibly ruthlessly as Chancellor, and all arms of government knew there was going to be progress made."