A £15bn plan to connect the North has the joint backing of organisations which together represent 12,000 businesses.
The One North 16-year proposal sets out how transport and connectivity infrastructure could transform the region into an economic powerhouse.
It covers air, roads, ports and rail and includes a high-speed east-west route that will speed up journey times between cities.
Now, six Chambers of Commerce have written to Chancellor George Osborne to urge him to back the plan - put forward by local authorities in Manchester, Liverpool, Leeds, Newcastle and Sheffield in July - in his Autumn Statement on December 3.
The letter was signed by the chief executives of the North East Chamber of Commerce, Hull and Humber Chamber of Commerce, Liverpool and Sefton Chambers of Commerce, Sheffield Chamber of Commerce and Industry, West and North Yorkshire Chamber of Commerce.
NECC chief executive, James Ramsbotham, said: “Our members are very much behind the principle of improved connectivity across the North of England, which will unlock the huge assets within the northern economy.
“A united northern chambers network stands ready to work with our local authorities and the Government to ensure this initiative delivers benefits across the North and meets businesses’ expectations.
“The local authorities that have pushed the project to this point must be congratulated.
“Infrastructure in the North has been under-developed for decades and addressing this is essential to achieve economic rebalancing and create the ‘Northern Powerhouse’ that Government has spoken of.
“While transport is by no means our members’ sole concern, it is consistently a high priority across all of our organisations. We therefore urge progress to ensure the opportunity to deliver these investments is not missed.”
The Chambers say is critical that support for this project expands beyond the local authorities driving it, and they point to the strategic importance of the automotive cluster around Nissan in Sunderland and the offshore industry on the North Sea coast and the largest integrated chemicals plant in the UK in Tees Valley.
Ed Cox, director of the think tank IPPR North, said innovation is vital and a variety of proposals was needed.
He said: “The Chancellor has given every indication that he will announce significant infrastructure investment for the North of England in his forthcoming Autumn Statement.
“This is most welcome but the North of England needs a pipeline of proposals for future investment that not only ensure on-going investment, but also shape the kind of economy the North of England needs to become.
“The One North proposal presents a clear, fundable and ambitious plan for infrastructure in the North and may well become the basis upon which the so-called ‘Northern Powerhouse’ of interconnected cities will be built in the next two decades.”
Mr Ramsbotham added a failure to support the One North proposal would represent a missed opportunity.
He said: “The North has the capacity to support much greater levels of economic activity. There is available land for development, at a cheaper cost, than many parts of the South. Development can also be delivered without putting the same pressure on environmental resources, such as water.
“In supporting One North, the Northern Chambers of Commerce are calling on other organisations across the North to work together, to ensure the opportunity to transform connectivity across the North of England is grasped.
“We expect the strategy to be given a high priority by local authorities and the Government with Chambers ready to play a part in articulating business views on proposals and helping to develop projects further.
“A strong commitment to deliver this strategy should be made in the Autumn Statement of 2014, receiving cross-party support to give confidence that a 15-year investment plan will be seen through by any future governments over that period.”