Stars of television, music and sport have joined the battle to save a huge swathe of wildlife-rich countryside from being developed next to a popular beauty spot.

TV's best-known duo Ant and Dec, former Swindon Town manager and former Manchester United and Scotland player Lou Macari, and Swindon-born singer Gilbert O'Sullivan have backed the cause.

Campaigners have also amassed well in excess of 40,000 signatures to halt plans for 1,800 houses, a university campus and offices being built next to Coate Water Country Park.

The move to stop the £500 million development is the largest protest campaign mounted in Swindon for more than a decade.

The Swindon Gateway development has been earmarked for farmland on the edge of Coate Park, a Site of Special Scientific Interest (SSSI) which is known as a area for migrating birds.

The Save Coate group claims the project would have a catastrophic effect on the 56-acre site, which is home to dozens of rare bird species.

Felicity Cobb, of the Save Coate Campaign (SCC), said: ''Ant and Dec were in the area and kindly signed our petition against the development.

"They were very pleased to do so when we told them the background and the threat to wildlife and the countryside.

''Their names are now alongside more than 41,000 other people in the region who object strongly to this proposal, which we believe would be catastrophic for the park."

Ant and Dec, Geordie lads Anthony McPartlin and Declan Donnelly, both 32, were in Swindon for a bash at their pal Jonathan Wilkes' country home.

Mr Wilkes' mother-in-law Pat Wheeler, a member of the SCC, collected their signatures.

Honorary director of the Wildfowl and Wetlands Trust, Gloucestershire -based Lady Philippa Scott has also backed the campaign, describing the threat to wild birds at Coate Water as shocking.

Another supporter is Lord Apsley, of Cirencester Park, who signed the petition and wrote two pages of A4 offering encouragement and support to the group.

His letter says: "The scale of this development proposal highlights the inadequacies of the new Regional Spacial Strategy which forces development into restrictive areas, rather than allowing development to reach out into some far more suitable areas within the district's or borough's hinterlands. "I am no planning expert but I do sympathise with your cause.

"I wish you every success with this challenge and I hope that you achieve a successful outcome."

The companies behind the proposals, house builders Redrow Homes and Persimmon Homes, say the development would help fill fast-growing Swindon's Government housing quota for the coming years.

They say it would also help fulfil the town's dream of having a university and are involved in "advanced talks" with a potential university partner to advance the scheme. However, angry green campaigners describe the area as the last pocket of unspoiled countryside close to Swindon which they have vowed to do everything possible to protect.