The High Court has blocked moves to allow pressure groups the right to run advertisements on television and radio by ruling that they are "political".
If the Divisional Court had sided with an animal rights group in an important test case, it would have opened the door to a flurry of broadcast campaigns by groups such as Amnesty International and Make Poverty History. However, Animal Defenders International vowed to fight on and was given leave to appeal to the House of Lords, a move it is considering.
ADI argued that the long-standing ban on political advertising in Britain, reinforced by the 2003 Communications Act, breaches the free speech provisions of the European Convention on Human Rights. It brought the case after a TV campaign was outlawed last year. Called "My mate's a primate", it condemned the use of primates for commercial interests such as circuses, films and advertising.
Make Poverty History and Amnesty International have also fallen foul of the rules, which are mainly designed to stop political parties advertising on TV and radio.
Tim Phillips, ADI's campaigns director, said: "This may be the letter of the law, but it is not justice. There is a considerable inequity here, with government and big businesses able to use the broadcast media while their critics like ourselves excluded.
"It is currently legal to use performing chimpanzees and monkeys to advertise anything on television. Yet when we produce an advert questioning this and asking people to consider how the animals are trained and treated, it is banned out of hand."
Dismissing ADI's challenge, Lord Justice Auld and Mr Justice Ouseley ruled that the ban was not incompatible with the European convention. Lord Justice Auld said the need for restrictions on "political/social advocacy" through media advertising outside election periods "has been convincingly shown".
He ruled: "At root (the ban) supports the soundness of the framework for democratic public debate." But the judges ruled that the case raised human rights issues of general public importance which were "appropriate" to be considered by the House of Lords.