The president of Shechita UK has urged the community to lobby MPs to prevent new EU regulations requiring kosher meat to be labelled "meat from slaughter without stunning".
Last month the European Parliament voted in favour of the amendment to the provision of food information to consumers, just two weeks after New Zealand banned kosher slaughter.
Henry Grunwald QC urged the Board of Deputies on Sunday to contact their MPs before the bill comes back for discussion in September.
The ruling, which only applies to food from religious slaughter, has been widely condemned by the Jewish community. Mr Grunwald said kosher prices could rocket because the non-kosher market, which takes the 70 per cent of shechita-slaughtered meat not permitted to Jewish consumers, might be deterred by the labelling.
He said: "We will do everything we can to make sure this does not become European law. We're not going to allow a discriminatory amendment to stand in EU parliament which singles out one method of slaughter."
In a joint statement, the Rabbis and Imams Advisory Group of the Chief Rabbi's Office, and the inter-faith organisation, Faith Matters, said: "We support the concept of fair and universal labelling, but believe that such an amendment is naked discrimination.
"It singles out religious communities who have been extremely careful to undertake humane food preparation for thousands of years."