Nicolas Sarkozy appeared to be trying to out-play far-right leader Marine Le Pen at her own game last Sunday when he told a Bordeaux crowd: "Let us recognise the right for everyone to know what they are eating…

"Meat should be labelled according to the way the animal is slaughtered," he added.

The French President's statement was apparently a response to an attack a fortnight ago by Ms Le Pen on Parisian supermarkets, which she claimed sold only meat from animals slaughtered without pre-stunning.

Mr Sarkozy seemed to have decided that the issue raised by Ms Le Pen was worrying a sufficient number of his would-be voters to revisit it ahead of the presidential election in April.

The figures used by Ms Le Pen to prove her argument were denied by the head of the French beef industry.

Originally, two days after Ms Le Pen's statement, Mr Sarkozy had tried to downplay the issue. On a visit to Paris's largest meat market in Rungis, he said: "This polemic is irrelevant, each year some 200,000 metric tons of meat are consumed in the Paris area, of which 2.5 per cent is kosher and halal."

Last week, National Front lawyer and Marine Le Pen's spokesperson Wallerand de Saint-Just filed a lawsuit against a number of supermarkets for "fraud and cruelty towards animals" on behalf of a consumer association and an animal rights group, both of which are closely associated with the National Front. "Fraud" refers to the National Front's claim that consumers were unaware that they were buying halal or kosher meat.

This is worrying both the halal and the kosher meat industry. As Shechita UK put it, labelling meat would be "could imperil the viability of shechitah in the UK and across Europe… If that meat were to be labelled as 'meat from slaughter without stunning' the market value of the product would drop, this could in turn represent a large financial loss for the abattoirs that produce kosher meat. This would drive the price of kosher meat up to a level where many would be unable to afford it."

Meanwhile, on Monday, the French Prime Minister François Fillon waded into the controversy, agreeing with Mr Sarkozy that halal and kosher meat should be labelled: "One cannot request the traceability of food and refuse to tell the French what they are eating. Religions ought to think about maintaining traditions that have little to do with current science, technology and health issues. We are in a modern country; there are ancestral traditions that are not very significant any more."