One Yorkshire backers believe the fact that Leeds is supporting the plan could prove crucial given Chancellor Philip Hammond has previously declared his desire to see the city secure a devolution deal.
The Government has previously rejected the proposed Leeds City Region devolution deal following concerns from Conservative MPs and North Yorkshire County Council.
Ministers have suggested Leeds could be part of a Greater Yorkshire deal covering all of the region outside South Yorkshire.
But the Government will be told Greater Yorkshire is politically undeliverable because of the opposition of rank-and-file Labour councillors.
One Yorkshire will be presented as the only devolution plan on the table which will deliver an agreement including Leeds.
Northern Powerhouse Minister Jake Berry reiterated the Government’s opposition to One Yorkshire in a special Commons debate on Tuesday night.
The Government wants the Sheffield City Region deal, negotiated with Barnsley, Doncaster, Sheffield and Rotherham two years ago, to go ahead and for the rest of Yorkshire to secure a separate deal.
Faced with determined resistance from the Department for Communities and Local Government, councils backing One Yorkshire will focus on making the economic case to the Treasury.
In the meantime, the Government’s determination to push ahead with the Sheffield City Region deal will mean an election for a metro-mayor for the area in May next year.
The election will take place despite Barnsley and Doncaster having withdrawn their support for the Sheffield City Region deal which, for legal reasons, will mean the mayor has few powers or access to the £30m a year promised under the agreement.
The Conservatives have now confirmed that they will begin the process of selecting a candidate for the election.
But Labour is not yet moving to choose who will stand for the party in May.
A Labour spokesman said: “There is no timetable for a selection process.”
Areas across the country already have devolution deals giving them more powers and money wielded by metro-mayors.
Theresa May will today meet Greater Manchester’s metro-mayor, former health secretary Andy Burnham, when she will pledge the Government’s ongoing commitment to the Northern Powerhouse idea to accelerate growth in the North of England.
Speaking ahead of her visit, Mrs May said: “The Northern Powerhouse is at the core of our work to spread growth across the entire country.”
She added: “Over the coming months I will be meeting leaders from across the Northern Powerhouse, starting today in Manchester, to talk about how we can progress this vital agenda.”
The Local Government Information Unit has today published a report suggesting the creation of a new mayors’ senate giving elected mayors a role in policy-making.
LGIU chief executive Jonathan Carr-West said: “Democracy is at a crossroads. We cannot rely on central government alone to guide us through the enormous challenges that lie ahead.”