Environmentalist Dr David Bellamy is threatening to chain himself to a wind farm planned for a Cumbria hillside.
The wind farm will be the largest seen in Cumbria
The TV botanist made the threat as hundreds of protesters marched over land near Whinash, on the edge of the Lake District at the weekend.
Renewable Development Company and West Coast Energy want to build 27 turbines, each almost 400ft high, generating enough power for 46,000 homes.
But protesters say the turbines will damage wildlife and the landscape.
The £55m plan would involve turbines being spread over a four-mile site, between Tebay and Shap overlooking the M6, and would generate 57 megawatts of electricity.
About 300 protesters gathered near the site over the weekend, including Dr Bellamy and broadcaster Eric Robson, who is also chairman of the Cumbria Tourist Board.
Dr Bellamy: Turbines are "mess of metal"
Dr Bellamy said he was prepared to take direct action, including chaining himself to one of the turbines, which he dubbed a "mess of metal which will block out what is the shop window of the Lake District."
Mr Robson added: "If we do not stop this, generations to come will look back and wonder what the hell we were doing.
"We have to stop it. We have to mobilise everything in our power to stop it."
The Cumbria Wildlife Trust says it is also concerned about the impact the wind farm will have on an areas of so-called blanket bog.
The trust is worried about the possible impact of laying down the turbine feet or laying roads over the surface.
Renewable Development Company and West Coast Energy have said they have consulted a number of environmental groups in the run-up to submitting plans.
Because of the size of the project the Department for Trade and Industry (DTI) will be responsible for planning consent, instead of Eden Valley Council, in whose area the wind farm will be sited.