CONSERVATIONISTS fear the route of the Commonwealth Games mountain bike race will cause permanent environmental damage in Rivington.

Thousands of people are expected to line the route of the race to watch more than 40 competitors use the off-road track.

But that, say environmentalists, is likely to upset the natural habitat in the area.

Tony Johnson, conservation officer for Bolton Royal Society for the Protection of Birds, has raised concern that the race -- taking place this summer -- will disrupt the bird population.

He said the free event was being held in the breeding season and he wanted to see measures put in place to protect them. Many people will visit the area in the space of a few days and that is surely going to be disruptive," he said.

"We still don't know what the policing or marshalling will be like. Are people going to be stopped from entering certain areas?"

The group has raised the issue at various meetings over the past few months.

It was one of a number of organisations which objected to the pruning of trees along the route.

Television producers said the trees were overgrown and would have blocked signals from their motorbike cameramen to a helicopter flying overhead.

The conservationists, however, said cutting them back would affect animals and birds in the area.

Mr Johnson said: "Rivington is a biologically important site but it seems nobody is respecting that.

"We want to know what will happen after the event as much as what will happen during it."

A spokesman for the event said: "Manchester 2002, in conjunction with the Local Authority, is committed to ensuring that there will be no permanent environmental damage to the mountain bike site at Rivington.

"We will provide sufficient well-trained marshals to manage the route, which will not exist after the Games."