Naturalist David Bellamy has backed a legal challenge to stop a £60m tourist attraction being built on national park land in Pembrokeshire.
David Bellamy claims the Welsh countryside is being lost
The broadcaster says overdevelopment is 'downgrading' the Welsh countryside and believes park land is 'sacrosanct'.
The Council for National Parks is to take the Pembrokeshire Coast National Park Authority to the High Court over its backing for the Bluestone project.
But the developer says the move is a "predictable delaying tactic".
Part of the 500-acre leisure and sports village, which would create 600 permanent jobs, is on land belonging to the national park.
Its members voted in January to back the scheme.
But the council, which acts as a watchdog for national parks, says the authority has contravened its own policies.
Speaking on BBC Radio Wales, Mr Bellamy said: "My concerns are that we are a very small island with almost 60 million people living in it, and that our national parks are pretty sacrosanct.
"I would say it's a prime example of what is there at the heart of the national parks.
"They really should not be being impugned by large building developments.
"The national park down there is a very very beautiful and wonderful place being used by a lot of people
"Much of Wales is already being covered by what I call the satanic mills of wind factories and the peace and the beauty is gone forever.
"So I would have thought it's important not to develop any more of the national parks."
He said the park should have helped Bluestone bosses find an alternative site outside its boundaries.
"There are areas outside the park boundaries where overgrazing and the wrong form of agriculture has already downgraded the biodiversity and the heritage of the countryside.
"Why did the national park authority not find a piece of land like that?"
Bluestone chief executive William McNamara said he had expected the legal action which is being taken by the Council for National Parks.
"This is serious because if they were successful, we're talking 600 full-time year- round jobs in Pembrokeshire and we find it very tiresome at this stage.," he said.
"The reality is this proposal has been democratically voted in. What they are challenging is that they don't like the decision."