A contender for the French presidency has been accused of exploiting community tensions by falsely claiming that all the meat delivered in the Paris region is slaughtered according to halal procedures.
The row offers further signs that Marine Le Pen, the far-right leader of the Front National (FN), is abandoning attempts to appear more moderate than her father and predecessor, Jean-Marie, whose remarks led to convictions for racist language.
In the past, Miss Le Pen has claimed to be against the "Islamification" of France rather than anti-Islam.
But as the elections approach, she has become more strident, on one occasion comparing Muslims praying in French streets, when unable to worship in crowded mosques, to the Nazi occupation during the Second World War.
In the latest controversy, her party intends to go to court complaining of "misrepresentation", on the grounds that the industry or official regulators - the legal action is "against X", meaning no defendant is identified - were failing to inform Parisians they were buying halal meat.
Those who disapprove of halal methods cite the failure to stun animals before slaughter. Miss Le Pen says that if elected - not considered a likely outcome - she would make this illegal.
Even when doubt was cast on the truth of her claims about meat sold in the Paris region, she persisted with the charge that the French government had deceived the public.
Ms Le Pen lags behind both Nicolas Sarkozy, seeking his second term as president, and Francois Hollande, the socialist front-runner, in the polls. She has only three weeks to secure the 500 mayors' signatures needed to stand.
In the halal controversy, she seized on a television report that said all slaughterhouses in the Ile de Paris region, with the exception of one handling only pork, killed livestock according to halal custom.
She interpreted this as meaning all the meat distributed in greater Paris was "unbeknown to the consumer, exclusively halal meat", adding: "This is a real deception. The government has been aware of it for months."
But Mr Sarkozy, supported by industry leaders, pointed out that the three abattoirs featured in the report in fact supplied only 2.5 per cent of the Paris region's needs, the rest being distributed elsewhere in France. The percentage included kosher as well as halal meat.
The president said Miss Le Pen had her facts wrong and had created an artificial controversy. He asked: "To throw suspicion on craftsmen, merchants, breeders to win few votes, is that to be the level of debate?"
However, the FN leader merely modified her attack saying it remained true that all meat distributed in the region could be suspected of being halal. Without clear labelling, she said, "neither you nor I know which is halal and which is not".
This prompted the left-of-centre news magazine Nouvel Observateur to award her three "Pinocchios", its highest level of rebuke for public figures and reserved for a "gross error or premeditated lie with malice. The conservative Le Figaro also denounced the FN for provoking a "false scandal". Ajib.fr, a news website aimed at French Muslims, reported this week on the case of a journalist, Claire Checcaglin, who infiltrated FN for eight months and found "commonplace or even obsessional racism against Islam".
In the run-up to the election, which starts with the first round on April 22, Miss Le Pen has been keen to attract disillusioned voters from Mr Sarkozy's centre-right UMP party.
Opinion polls still indicate that the likeliest winner is Mr Hollande, with his party well-placed to take legislative power in parliamentary elections.
The latest survey, by the CSA polling institute, puts Mr Hollande narrowly ahead of Mr Sarkozy for the first round with Miss Le Pen eliminated, but on 56 per cent, a lead of 12 points, for the May 6 decider.
Voting intentions vary in different parts of France. A poll conducted for the newspaper La Voix du Nord found 25 per cent of respondents in its area of northern France would definitely or probably vote for the FN.
Most French Muslims, estimated to number five million to seven million though no official records are kept, might be expected to vote for the socialists, but this is open to doubt.
Mohammed Moussaoui, president of the French Muslim Council (CFCM), said recently he did not believe there was any such thing as a "Muslim vote" in France.
"The Muslim community is crossed by the same political currents that run through the national community," he said in a radio interview. "We are a body representing the Muslim faith, we have no instructions to give to our citizens. We respect their political choices."
However, Mr Moussaoui also spoke of rising Muslim concern about the far right. "There is a minority of people who try to poison the lives of our citizens. Anti-Muslim acts have increased this year by almost 30 per cent, notably in the desecration of mosques.
"I believe in the rule of law. All citizens should feel safe, protected, respected. What worries us is that the ideas of this party are gaining momentum across our society and our country".
Yesterday, French media reported that "the polemic launched by Miss Le Pen" had cost her party a senior figure. Paul Lamoitier is an FN councillor for the northern region of Nord-Pas-de-Calais, where - as a wholesale butcher - he is also one of the leading suppliers of halal meat.
*With additional reporting by Agence France-Presse