British lawyers are set to go to the European Court of Justice in a bid to overturn a controversial proposed EU directive, which could cripple scores of small firms in the £335 million ($629 million) food supplements sector.

They will argue in Luxembourg this week that a directive banning thousands of common food supplements, due to take effect in August, is incompatible with community law.

The case has been brought amid fears the 2002 Food Supplements Directive would impose huge regulatory costs on suppliers, which would lead to many of them going bankrupt.

The legislation would threaten up to 5,000 common products, containing more than 200 nutrients, used safely in specialist supplements for many years, because they are not on the "positive list" of permitted substances.

Only manufacturers who submit detailed scientific dossiers proving their ingredients are safe by July 12 this year would be allowed to escape the directive's provisions, and then only until the end of 2009.

The British Health Food Manufacturers Association (HFMA), the National Association of Health Stores (NAHS) and Alliance for Natural Health will challenge the ruling.

The organizations also argue millions of people oppose the curbs on their freedom to choose what they consume.

Andrew Lockley, head of public law at Irwin Mitchell, legal adviser to the HFMA and NAHS, said, "This argument really reflects a culture clash between Britain, where a third of women and a quarter of men take health-food supplements, with the market thought to be worth at least £335 million ($629 million) a year, and continental Europe, where these products are traditionally treated like medicines.

"We believe our appeal presents the court with an important chance to demonstrate that it can respond to the widely felt concerns of people and businesses, which have not been taken into account sufficiently by community legislation which lacks proper democratic accountability."

Although challenges to European directives are rare, the Court of Justice annulled a 2001 attempt to ban tobacco advertising, saying it had been adopted on the wrong legal basis and that measures to protect public health were matters for member states.