A campaign has been launched in a bid to scupper plans to build the world's longest rope footbridge over the River Tees.

The 550ft long structure is being planned to span the river at a height of 150ft on the site of a demolished railway viaduct near Barnard Castle, County Durham.

The proposal by Teesdale Marketing, a voluntary body set up to boost the local economy, and has already been approved in principle by Teesdale District Council.

But yesterday retired airline pilot Robin Rackham became co-ordinator of campaign to oppose the £4.5 million project, expected to attract up to 100,000 visitors a year.

Mr Rackham, owner of Lartington Hall and a former district councillor, said: "I feel it totally wrong that £35,000 of public funds has already been spent on this scheme.

"The bridge itself might be acceptable, but the routes needed to get visitors to it would cause far too much impact on woods, the local golf course and the environment generally."

He is linking up the opposition on behalf of Barnard Castle Golf Club, the Campaign for the Protection of Rural England, historian Alan Wilkinson and others.

He aims to hold a public meeting in the town's Witham Hall on Thursday December 18 to outline the opposition unless Teesdale Marketing arranges a public meeting in the meantime.

Mr Rackham added: "The £4.5 million is expected to come from the National Lottery Fund, One NorthEast and Durham County Council. I am writing to ask them not to give any money at all as the project would do far more harm than good."

Chris Dauber, secretary of Teesdale Marketing, said: "Just about everyone I've spoken to supports our scheme. We have made it clear all along that we believe it will help the local economy. But the plans still have some way to go."

The organisation hopes to have the bridge ready by late summer 2005, and to name it after the late Queen Mother. Prince Charles may be invited to officially open it.

District councillor Ken Coates said: "I think the bridge could be good for the town but only if a large car park is created first. It is no good attracting more visitors if there is nowhere for them to park."

The Golf Club has objected to the scheme, claiming people using a new access road would be in danger from flying golf balls.