Its decision goes against an opinion delivered by the same court's advocate-general in April, advising that the rules should be scrapped because they contravene basic EU principles of “legal protection, legal certainty and sound administration."

Under the directive, health food companies have to submit natural remedies, vitamin supplements and mineral plant extracts -- many of them long-established shelf items in U.K. stores -- for approval and inclusion on a list of recognized food supplements

Around a third of British women and a quarter of British men use the products. The U.K. market for them is worth £300 million ($520 million) a year.

Tony Blair is believed to be opposed to the directive -- regarding it as too heavy-handed.

John Bowis, the Conservative Party's health spokesman in the European Parliament, called the verdict '”a defeat for common sense and a victory for overregulation.”

The Luxembourg judges cited both trade and health grounds as reasons for backing the changes, which should now be implemented in Britain.

They said, “A 'positive list' system is appropriate for securing the free movement of food supplements and ensuring the protection of human health.”

However, Bowis insisted the directive is more about interfering in people's lives than their health.

He estimated that about 300 nutrient sources would now have to be banned in the U.K. unless they are able to win a place on the positive list.

This, he claimed, would require “excessive levels of testing and red tape.”