Proposals to implement the new EU food supplements directive in the UK were rejected yesterday by the government's upper house, the House of Lords, who called on Blair to revoke the regulations.
But the vote, won by a majority of 53, cannot stall the directive, due to be implemented in August 2005.
The motion, proposed by health spokesman for the Conservative party Earl Howe, called on ministers to renegotiate the directive with the European Commission, so that nutrients currently marketed in the UK in supplements can remain on sale.
However revoking the directive would mean a breach of obligations under the EC Treaty and would result in heavy fines for the UK.
The new directive, designed to harmonise the supplements trade across the European community, leaves around 280 nutrients and nutrient sources, currently available in the UK, off the list of permitted substances. The legislation provides an option for supplement manufacturers to submit dossiers of scientific evidence supporting a nutrient, for inclusion on the list, however so far very few dossiers have been submitted.
The UK has one of the largest supplement markets in Europe, thought to be worth £860 million in annual turnover, according to a BBC report. It has seen the most determined opposition to the legislation, championed by consumer group Consumers for Health Choice.
"This vote sends a powerful message to the government that the Food Supplements Directive is unacceptable, "Earl Howe told reporters in the UK.