Countryside campaigners have accused poster companies of vetoing an advertising blitz aimed at opposing the Government's plans to allow more billboards in rural areas.
The Council for the Protection of Rural England (CPRE) wanted to run a poster campaign in urban areas warning about the threat to the countryside if ministers go ahead with plans to relax planning controls over billboards.
Instead, the CPRE will launch a pounds 20,000 national press push through Target next week, when it will accuse the four biggest poster companies of censoring its billboard campaign by refusing to provide sites.
The press ad shows a rural area dominated by posters urging people to 'buy' various goods, and says: 'Bye, bye, countryside.'
Tony Burton, the CPRE's assistant director, said that the decision demonstrated the power of the poster companies to pursue their 'vested interests'.
He added: 'We think this raises much wider issues about the role of the companies in public debate because they have the power to veto what the public can see and talk about.'
Burton welcomed signals from Whitehall that the Government may be thinking twice about allowing more billboards in rural areas.
Ministers now face a dilemma because they are keen to allow Britain's hard-pressed farmers to put up posters to help them boost their income.