Holding banners, they marched through the village of Benington against plans to erect three 120metre-high wind turbines on High Elms Lane, between Benington, Aston and Watton-at-Stone.

The project, which is due to be submitted for planning permission to East Herts District Council in early to mid November by local landowners RH Bott and Sons, is expected to supply enough power for around 3,000 homes if it is given the go ahead.

But residents in the surrounding area are concerned that the wind farm will intrude on the Hertfordshire landscape, create noise pollution and shadow flickers, prevent people using some bridleways and affect wildlife and natural habitats.

Rowan O'Duffy of the Stop Benington Wind Farm (SBWF) action group, said: "Areas of outstanding natural beauty like this are precious and need to be looked after.

"We must save the historical landscape of Cotton Lane and High Elms Lane. The significant change to the character and appearance of the landscape caused by wind turbines hugely outweighs the benefits in terms of renewable energy generation."

Author Frederick Forsyth, Kevin Fitzgerald, the director of the Campaign to Protect Rural England (CPRE) and MP for North East Herts, Oliver Heald, who has constituents in Watton-at-Stone, were among those who took part.

Mr Heald said: "I'm a supporter of wind energy but in the right place. I don't think it should spoil one of the most beautiful valleys in Hertford-shire with three structures that are almost as high as the London Eye.

"This is a very precious small scale landscape in the most populated county in the country.

"I have had hundreds of people contact me about this. They are saying by all means have wind farms but in appropriate places such as by motorways.