Campaign Against Stevenage Expansion chairman Tim Akeroyd said they would now consider High Court action to get the decision set aside.

He said a swatch of pretty countryside would be lost for ever.

The move has been welcomed by Stevenage Borough Council which says homes are desperately needed west of the town.

I am concerned that there is no infrastructure to support the development North Herts Council chairman Lynda Needham

Mr Akeroyd said: "I am obviously intensely disappointed, not least because the (planning) inspector found that all the land is green belt.

"The Deputy Prime Minister went on the record to say that there would be no development of the green belt. We have been bitterly let down by Prescott - he has not acted in an honourable way.

"This huge development is not necessary. The A1M motorway provided a barrier protecting unspoilt countryside - now that has been breached we don't know where it will stop."

Mr Akeroyd said thousands of people opposed the expansion with Stevenage Borough Council being its only supporter.

North Herts Council chairman Lynda Needham said: "We opposed the loss of countryside and the detrimental effect on the green belt.

"I am concerned that there is no infrastructure to support the development. Anyone who uses the road and rail links around here realise how congested they are. The bus services are totally inadequate. There are other problems with water supply and recycling waste.

"I will be talking to our officers about the caveats the Deputy Prime Minister has put in. "

But the leader of Stevenage Borough Council Brian Hall described those opposing the development as "Luddites."

Mr Hall said 800 extra homes a year were needed to support the borough's existing population and there was already a shortfall each year of 400.

Cheaper homes

"Homes are very expensive in this area and we are asking for 25% low cost homes. They are needed in both Stevenage and North Hertfordshire. People come to us and say they need cheaper homes in the area to be able to afford to live.

"Most of the people who say 'don't build on the countryside' live in the countryside themselves. They are Luddites. The experts and specialists who look at planning say an urban expansion like this is preferable to new developments.