Lotus has been based in Hethel, Norfolk, since 1966

Complaints were upheld against two leaflets by Norfolk-based RUNGA (Are You Naive Gullible Apathetic).

The group was set up to fight plans for three turbines to supply electricity at the Lotus Cars plant near Norwich.

Claims house prices would be hit, noise would disturb sleep and taxpayers would be charged, misled people, the Advertising Standards Authority said.

RUNGA did not reply to the Advertising Standards Authority investigation and failed to justify the claims made in their leaflets.

Rejection

The authority said: "We did not receive any substantiation in support of the claims property would be devalued by between 15% and 20% or TV pictures would probably be affected."

Other claims that were dismissed included the assertion that constant noise (24 hours a day) would be heard up to 5 miles away and sleep would be affected.

Developers Ecotricity challenged the leaflets which claimed taxes would be used to build the turbines and none of electricity would go to the car plant.

Lotus Cars at Hethel aims to become self-sufficient in energy by building the wind farm on its site and is now appealing against the rejection of a planning permission application by South Norfolk District Council.