The Government inspector appointed to review the blueprint for the area started his seven-week examination yesterday.

On behalf of the Secretary of State, Eric Searle will assess the plans for tens of thousands of new homes in Kettering, Wellingborough, Corby and East Northamptonshire.

He will determine whether the plans pass nine tests, including community involvement and effectiveness, and will also assess the levels of infrastructure and the area's economic regeneration.

In the opening session of the inquiry at Kettering Conference Centre, Thurston Drive, Mr Searle put the first of a series of questions to the North Northamptonshire Joint Planning Unit,

The unit has put together the plans, called the Core Spatial Strategy, which could provide the framework for development in the towns.

Chairman of Stop the Over-Development of Northamptonshire Sir Peter Fry spoke at the hearing.

He said: "Only last week it was admitted that the sewage capacity in the area would be exhausted by those houses already being built, without the urban extensions that are planned. One accident on the A14 last week completely closed Kettering down. There's very considerable concern about the infrastructure."

Developers said that while a study of the A14 is carried out, interim measures are being considered so that development is not held up.

David Lock, for Bee Bee Developments, said: "We are to be one of the great growth areas for England and we will act as a safety valve for the rest of the country. The object is not only to meet housing needs in north Northamptonshire but to make a contribution to tackling housing shortages in England."