We want 100 per cent devolution across the North, business leaders urge Boris Johnson

The Devo 100 letter, signed by senior business figures from companies including Bruntwood, Leeds Bradford Airport and Associated British Ports, urged Mr Johnson to address the gaps in devolution which were not addressed by his predecessor Theresa May.

They called for the new Prime Minister to deliver on the aims outlined in The Yorkshire Post's Power up the North campaign by devolving powers currently in Whitehall to elected mayors and local leaders, allowing them to drive forward the economic vision of the Northern Powerhouse.

Currently, the Northern Powerhouse has elected mayors in five regions – Liverpool City Region, Greater Manchester, Tees Valley, Sheffield City Region and North of Tyne. However, negotiation of all of those deals commenced before the last government took office in July 2016.

The five existing deals mean only 47.1 per cent of the North is now governed by a metro mayor. One of the biggest gaps is in Yorkshire, which has yet to have a fully-implemented devolution deal despite the election of Dan Jarvis in the Sheffield City Region last year.

A lack of local agreement means the deal signed by leaders in Sheffield, Doncaster, Rotherham and Barnsley in 2015 has not yet become a reality and Mr Jarvis has none of the powers or resources of other metro mayors.

Last month, Yorkshire leaders urged Mr Johnson to re-open talks on a possible One Yorkshire deal, which would see a host of powers and control of budgets handed over to a region-wide mayor.

The Prime Minister has previously backed devolution as a means of making the UK less centralised. In a major speech in Manchester last week he said: "Taking back control doesn’t just apply to Westminster regaining sovereignty from the EU. It means our cities and counties and towns becoming more self-governing.

"It means people taking more responsibility for their own communities. London and Manchester have boomed partly because they have had Mayors – some better than others, I would say, but all with the power to speak for their cities, to bang heads together, to get things done."

Today's letter says: "Today we are backing your commitment of devolution everywhere, and as leaders are backing 100 per cent devolution to cover every area of the North.

"As you have recognised, devolution allows faster, more responsive decision making and delivery, stimulating economies and better addressing the causes of social problems, not just dealing with their consequences.

"It is the next step in creating a Northern Powerhouse that can truly deliver for people, communities and businesses right across the North of England.

"You have pledged a government for every corner of this country, and we commit to work with you to achieve it with a law to guarantee a devolution framework with the transfer of powers as a right to our places."

Northern Powerhouse Partnership Vice-Chair Lord Jim O’Neill, who helped develop the concept while part of former Chancellor George Osborne's Treasury team, said: “As I recommended in my report for the Cities Growth Commission, it is only by devolving further powers that we will see the North pull its true weight in economic terms alongside interventions in transport, like the new line between Leeds and Manchester as part of Northern Powerhouse Rail, or closing the North-South gap in education.

“Under the previous administration led by Theresa May, we have seen not a single new devolution deal started since George Osborne and I left the government.

“I welcome the Prime Minister’s commitment made in Manchester last weekend promising communities a greater say over changes to transport, housing, public services and infrastructure and as business and civic leaders we are backing 100 per cent devolution to cover every area of the North.”