The busy A23, A27 and Brighton Mainline could be upgraded if the Government agrees to help fund a multi-billion-pound project.

Coast to Capital Local Enterprise Partnership (LEP) also plans to create 60,000 new jobs and build 27,000 new homes.

The LEP has asked the Government for £559 million in funding and has pledged to find another £550 million of public sector funding from local authorities and universities and colleges as well as a further £2.78 billion of private sector funding if the Growth Deal bid is successful.

In The Strategic Economic Plan the LEP warned Sussex’s infrastructure is reaching capacity and was no longer able to support growth if investment was not made.

John Peel OBE, outgoing LEP chairman, said: “Our plans are unashamedly bold but we are up to the challenge.

“With our international connections, the skills of our workforce and the competitive strengths of our businesses, this region has a lot to offer.

“However, our economic success will be hampered if we do not make critical investment across the board.”

Congestion at transport hotspots, key junctions and employment links would be improved and urgent flood defences boosted in Newhaven as well as at Shoreham harbour and airport.

Centres of excellence in digital, sustainable enterprise, advanced engineering and bioscience would be created, and every young person would be supported to make the transition from education to employment. Two new Enterprise Zones would be created at Newhaven and Bognor.

Although it is one of the most successful LEP areas in the UK, investment is essential to sustain and build economic success, the document argued.

Some areas were showing poor performance while the housing market needed “unblocking” to allow for growth.

Ron Crank, Coast to Capital chief executive, said: “I believe we’ve got a quality submission which stands up and tells a story about the Coast to Capital region and the importance of places like Brighton, Newhaven and Shoreham.

“We all recognise that investment has been lacking in infrastructure. I talk to business and I hear ‘congestion, congestion, congestion’.

“We need to make sure there’s more connectivity.”