Deputy Prime Minister John Prescott was expected to make his announcement on Friday, but the deadline has been extended until 20 September for more deliberations on the environmental impact of the project.

Provisional figures revealed opponents of the scheme outnumbered supporters by more than three to one.

Environmental groups say the delays demonstrate deep flaws in the project

'Deeply flawed'

Bryan Atkinson, from South Tyneside Friends of the Earth, told BBC Radio Newcastle there had been hundreds of objections.

"I think [Mr Prescott] has got to go to public inquiry on this because of the number of objections from local people and also the quality of the objections," he said.

"This is a deeply flawed project. We can't wait to get it to public inquiry where they will be told to get back to the drawing board."

Paul Fenwick, assistant engineer to the tunnel, said the delay was due to the complicated nature of the project.

"These government agencies have been asking for detailed information.

"It's quite complex, we have supplied it, they need time to absorb that information and that is why we have this delay."

The new tunnel, which is being put forward by the Tyne and Wear Passenger Transport Authority, would run between East Howden on the north bank and Jarrow on the south bank.