Darlington'S vision of becoming a vibrant gateway to the Tees Valley could be thwarted by a Highways Agency edict aimed at keeping down traffic on the A66.

The matter has become urgent now the agency has specified a limit to any future development at Darlington Great Park - the site between Lingfield Point and the A66 - to ensure the trunk road does not become overloaded.

Tuesday's cabinet meeting will hear a request from John Buxton, director of development and environment, to allow a £40,000 contract for consultants to carry out the first phase of the A66 Tees Valley Gateway study.

He said: "As a result of predicted traffic growth and the re-routing of traffic once the Darlington eastern transport corridor is open, capacity issues have been identified as significant concerns on the A66(T) around Darlington in the medium to longer term."

The study was necessary to ensure that this did not impede economic regeneration in both Darlington and the wider Tees Valley area, acting as a barrier to the objectives of the Tees Valley Vision.

It would consider:

* Improved heavy rail services between Darlington and Saltburn;

* Rapid transit proposals;

* New north-facing slip roads at the A66(M)/A1(M) junction;

* Creating a Darlington northern bypass;

* Dualling the single carriageway section of the A66 around Darlington;

* Constructing a cross-town route through Darlington from the A1(M) at Faverdale to the A66.

The development restriction would also apply to any other reasonable-sized development on the eastern side of Darlington which resulted in additional traffic.

Mr Buxton said if the volume of traffic on the A66 around Darlington could not be solved, the town could not act as a gateway to the Tees Valley and would not be part of the western growth corridor from Darlington to Middlesbrough and Stockton.

A steering group has been set up involving the Government Office, the Highways Agency, the North-East Assembly, One North-East, the Tees Valley Joint Strategy Unit and Darlington Council.

Its remit is to commission consultants and oversee the study process