Darlington's future prosperity and economic development could be jeopardised if a £118 million dual carriageway upgrade on one of the region's busiest roads is not approved, council leaders warned.

The Highways Agency is stalling over plans by Darlington Borough Council to upgrade a section of the A66 - between the roundabout near Great Burdon to the Reg Vardy roundabout - to make it into a dual carriageway.

But the Highways Agency has been put off by the cost and time commitments the venture would require.

The council argue that the A66 is a key road in linking Darlington and the A1 with Teesside, that will play a major role in the town's future economic prospects.

The Tees Valley Gateway Study, which was commissioned by the council to look into the situation, claims that: "The issue is important for future development of the airport, links to the port, generally to the development of the Tees Valley and east Darlington in particular."

However, the reluctance of the Highways Agency to back the plan has led to the council being forced to develop a £53 million alternative, which would see dualling between Great Burdon and the A66/A67 Morton Palms junction.

Speaking at the council cabinet meeting, leader John Williams slammed the Highways Agency for blocking the £118 million upgrade, but insisted campaigns for a full upgrade of the road would continue.

He said: "I am deeply disappointed that the Highways Agency does not see fit to fully dual the road.

"There is great enthusiasm and ambition for the future of Darlington, and our transport links should befit that.

"That such important plans to improve these factors should be turned down because of affordability is disappointing."

Coun Tony Richmond, leader of the Conservative group in Darlington, agreed that the full development of the A66 around the town was necessary.

He said: "The improvements are essential for the future prosperity and economy of the town."