The Sheffield City Region Mayor also praised the unity of those leaders for hitting back at the Government in the ongoing row over a One Yorkshire devolution deal.
On Thursday, 18 of the region’s 20 council leaders and Mr Jarvis gave a defiant response to the claim by new Local Government Secretary James Brokenshire that he was currently “not prepared” to discuss One Yorkshire.
The Mayor said: “I have been struck by the great unity, spirit and resolve shown by the Yorkshire leaders at every stage of this process.
“We are determined to stand together to secure the devolution deal that best serves the interests of the people of Yorkshire.
“We have always been clear about the strong case for Yorkshire devolution.
“A detailed proposal has been produced and we now seek a constructive, collaborative approach from Government to make that proposal a reality.”
‘United to deliver the will of Yorkshire’: Region’s leaders’ message to Government over devolution sagaMr Brokenshire’s letter said the Government would only enter into discussions about a wider devolution deal once the more limited Sheffield City Region deal, first agreed in 2015, was implemented in full.
The intervention came as a surprise to leaders in Yorkshire, who in March had submitted detailed proposals for what a One Yorkshire deal would look like and had not had a formal response.
After meeting in York on Thursday, they issued a joint statement on behalf of all Yorkshire’s councils, other than Sheffield and Rotherham, vowing to “deliver what the people of Yorkshire want, what the region deserves and what could benefit the whole of the UK”.
The leaders said they were “disappointed” that Mr Brokenshire had sent a three-paragraph letter “placing obstacles” in front of the proposed deal, which would see a Yorkshire mayor with powers and money devolved from Westminster, after having promised to give “careful consideration” to the proposals submitted in March.
One Yorkshire backers also made clear they “stand together - united to deliver One Yorkshire working with a constructive partner in Government”.
The leaders revealed they have tasked officers with continuing to develop the plan in line with demands set out by Government and called for Ministers to respond with a “constructive approach” and “rapid progress” in the coming weeks and months.
Following criticism of the economic rationale behind a One Yorkshire deal, they have ordered a study on the issue to report back “in the coming months”, and stated their willingness to attend talks in Westminster.
“The One Yorkshire proposal has the cross-party support of 18 authorities and the Mayor of the Sheffield City Region, ready to deliver a devolution deal right now which would offer huge benefits for the region and the wider UK economy,” they said.
“With the constructive support of the Government, an agreement can be in place and a Mayor for One Yorkshire elected by 2020. “
Battle lines have been drawn over the future of devolution in Yorkshire since last year.
Sheffield and Rotherham are the last remaining councils not to back One Yorkshire, remaining committed to the Sheffield deal.
But Doncaster and Barnsley leaders pulled out of the Sheffield deal, meaning that Mr Jarvis was elected in May with virtually no powers or resources.”