But the project is still in doubt because of the Government’s decision to put a £1.1bn road widening scheme on the adjacent A14 on hold.

Local planning bosses said development of the National Institute for Agricultural Botany (NIAB) site, between Huntingdon Road and Histon Road, would provide desperately-needed houses, plus a primary school and community facilities.

The Highways Agency has the power to veto developments if it fears new schemes will overload the trunk road network.

The Agency has told local officials that only 350 homes can be occupied on the NIAB site until improvements are made to the A14.

The A14 work was due to be undertaken by a consortium of Costain and Skanska, but was one of 12 to be put on hold by the Government until the autumn spending review.

Delays in the road widening have also cast doubt on plans for a 10,000-home prototype eco-town at Northstowe.