Plans by Amicus and the T&G unions to extend a campaign urging consumers to boycott Peugeot cars to radio ads have been dashed by legislation.

The unions are running a £1m boycott campaign in protest at the decision to close the Peugeot plant in Ryton in the Midlands, which started with a series of newspaper advertisements last week.

But their hopes of running radio ads in August were ended as section 15 of the Radio Advertising Standards code limits trade unions to advertising their services to members and expressly prevents them from making statements about disputes or from stating facts about employers.

Amicus general secretary Derek Simpson said: "It is outrageous that trade unions are prevented from explaining to the public the simple fact that Peugeot has sacked 2,000 people from a profitable plant in the Coventry in search of ever greater profits by exploiting low wages in Eastern Europe."

T&G general secretary Tony Woodley added: "The public needs to know we are fighting back with our members in Peugeot against the closure of a profitable car plant.They need to know the unions have put forward positive plans to save the factory which Peugeot has ignored.

"And the public needs to know there is support from industry experts, and now show business, for our campaign. The law has gagged us from saying this on the radio, but we'll say it all the same."