The Co-operative Group wants to build a 15,000-home eco-town on land it owns between Great Glen and Stoughton, a plan which was shortlisted by the Government in April last year.

The Department for Communities and Local Government, which is set to rule in the spring or early summer on which proposals go forward, has extended the consultation period until April 30.

Critics of the eco-town plan said it was 'astounding' the consultation process has been stretched to 20 weeks.

Dr Kevin Feltham, chairman of the Campaign Against the Stoughton Co-op Eco-Town, said: "It is clear that any final decisions about locations cannot now be made public until well into the summer, and this delay is costing people money as the value of houses in the Pennbury area have been seriously blighted by the whole uncertainty of the timetable and the Co-op's plans."

The DCLG said it wanted to give people more time to submit their views.