Weston Otmoor, the controversial proposed 15,000-home eco town, could only work if "substantial and exceptional innovation" was carried out to current plans.

The stark assessment comes as the Government today launched its second round of formal consultation on the proposed locations and standards for 12 eco-towns across the country.

All sites on the shortlist — including Weston-on-the-Green, between Kidlington and Bicester — have been graded A to C, with A meaning the site is suitable for development, B meaning it might be suitable and C meaning it would be suitable only if substantial and exceptional innovation took place.

Weston Otmoor is the only site currently ranked C.

However, in an surpise development, Oxfordshire might still have to find room for an eco-town, as Cherwell District Council has tabled an alternative to Weston Otmoor, it has been revealed.

The scheme - called North West Bicester (Cherwell) -has been included on the shortlist and given a B ranking.

Housing Minister Margaret Beckett will have the final say on which schemes get the go-ahead.