Ahead of Mr Johnson delivering a major speech in Yorkshire today, Gerald Jennings, the boss of the North and West Yorkshire Chambers of Commerce claimed backing HS2 would significantly boost not only the North but the UK as a whole.
The Prime Minister is due to speak today in front of northern political and business leaders at the the Convention of the North with NP11 conference at the Magna Science Adventure Centre in Rotherham.
Ahead of the speech, his second visit to Yorkshire in eight days, he was challenged by Yorkshire's only metro mayor Dan Jarvis to demonstrate his commitment to the North and unlocking its potential "through deeds, not words".
The Prime Minister is expected to reiterate his commitment to the Sheffield City Region devolution deal - which was signed in 2015 but has yet to be implemented - and negotiating with Leeds and West Yorkshire over a separate deal to transfer powers from Whitehall.
And he will announce that his government will create a new Northern Powerhouse growth body to drive forward the region’s economy, with powers to bring together major organisations.
The possibility of a new body run by northern leaders to boost the region's economy was first revealed by The Yorkshire Post last month.
In an article for this newspaper, chamber of commerce chairman Mr Jennings said the cost to Yorkshire, the North and the UK of not investing now and significantly in HS2 and the full rail network "cannot be underestimated".
He wrote: "I truly believe we will live to regret what would be a lost opportunity for generations to come.
"As the Convention for the North takes place in Rotherham, we urge the Prime Minister and his cabinet to recognise that a powerful northern economy with 21st century connectivity is not a zero sum game but will add significantly to UK plc."
Mr Jennings also took aim at opponents of HS2, urging them to think of future generations and back the scheme to provide faster travel between London and the North.
"When I hear naysayers say they’ll be long gone by the time HS2 arrives I like to remind them it’s not just about them. It’s about the next and future generations. Let’s move on from a rather self- absorbed if not selfish attitude of 'it’s all about me'.
"And after all 2030 or 2035 is in fact not that far away. If we don’t start now we’ll never!"
Separately, the Liverpool city region and Greater Manchester mayors, Steve Rotheram and Andy Burnham, said Mr Johnson's support for high speed rail in the North cannot be the only test of commitment to the region. They demanded the Government terminates the Northern rail franchise and works towards more local control of rail services.
In his speech today, Mr Johnson is expected to say: “It is time that we gave more people a say over the places where they live, and it is time that we gave you the proper ability to run things your way.
“We are going to maximise the power of the North. And we are going to make sure that it is people here who are in control over the things that matter to them."
He will add: “If we succeed in levelling up opportunity across our country, and if we truly put the power in your hands, then I believe you will do for the North – and for our whole country - what the railways did two centuries ago.
“That is the true potential of this Northern Powerhouse Partnership. And this is a Government that will back you to deliver it.”
In an interview last week with The Yorkshire Post, the PM said he was "mad keen" in principle on the One Yorkshire mayoral authority put forward by a cross-party group of the region's political leaders.
Director of the Northern Powerhouse Partnership Henri Murison said: “The Prime Minister needs to stand on the side of genuine devolution, with more powers for mayors like Andy Burnham, Dan Jarvis and their colleagues and deals for areas from Cheshire to much of Yorkshire which have so far missed out entirely.
“Any new growth body for the North should be accountable to and driven by those elected Mayors and civic leaders with a genuine mandate to represent the public, and have serious financial powers. The causes of the Brexit vote in the North were not so much about Europe in many places, but more about feeling a loss of control.
“If the North is to take back control it must be the Northern Powerhouse that shapes its own destiny. However much we trust Jake Berry MP as our voice at the Cabinet table, relying on Whitehall to back us and our plans to rebalance the country is not enough.
“From leading a revolution to decarbonise the country’s energy needs whilst growing our industry, backing Northern manufacturing, or closing the gap in how the most disadvantaged in our schools do, the Convention of the North will prioritise addressing productivity and unlocking economic potential. The Prime Minister should take note.”
Conservative Tees Valley mayor Ben Houchen said: "People buy into leadership, they buy into positivity, and they buy into a place on the move. Every job that we’ve created in the Tees Valley proves the devolution model is working.
"By using the powers I have as a metro mayor to focus on local priorities I’ve been able to drive the Tees Valley forward like never before.
“The people in the region that I represent didn’t vote to take back control and to bring powers back to the UK, for them to be just swallowed up by Westminster. Having more devolution will make a big difference, with even greater economic growth and brighter prospects for the people of the Tees Valley for generations to come.”
Arianna Giovannini, Interim Director of the think tank IPPR North said: “The fact that the Prime Minister has today indicated his support for the principle of devolution to the North is to be welcomed, but what we must see now is a shift from rhetoric to action.
“The North has seen a succession of Westminster politicians make a series of promises that they haven’t kept, and devolution to date has been too often dictated by central government. The region needs not words, but actions- spades in the ground, investments in people and infrastructure, and crucially real devolved power.
“It is in the national interest for everyone- Government and Northern leaders- to work together to move the Northern Powerhouse into a positive new phase. One that works for the whole of the North, and which is of the North, by the North, for the North.”