French extreme-right leader Marine Le Pen accused a top Socialist on Wednesday of using an ugly incident involving anti-Semitic youths as a weapon against her presidential prospects.
Le Pen, third in the polls ahead of the May election, said she condemned violence against Arnaud Montebourg and his broadcaster partner Audrey Pulvar but said there was no proof the attackers were from her anti-immigrant party.
Montebourg and Pulvar, who last week grilled Le Pen about her policies in a TV interview, said about 15 young men surrounded them as they left a Paris restaurant late Tuesday and chanted "Le Pen for president".
They shouted "France for the French" and "Juden, Juden, Juden" (which means Jews in German) before throwing glasses at the couple as they left the restaurant in the chic 16th district, Pulvar said in Twitter messages.
They also shouted "Kick the Yids out of Paris", according to the couple.
Montebourg, who is of mixed French and Algerian origin, said: "This shows that there is a climate within Mrs Le Pen's (National Front) party where racist speech... is made freely."
Marine Le Pen said Montebourg and Pulvar, who is of French Caribbean origin, were seeking to use Tuesday's incident to "attempt to tarnish my (election) campaign".
"It is being used in an absolutely scandalous and unworthy way by Ms Pulvar, who is totally stepping out of her role as a journalist, and her companion Mr Montebourg," she told reporters.
In a statement, Le Pen said she would file a defamation complaint against Montebourg, saying he "has absolutely no evidence for his slanders".
Le Pen has sought to reach out to a broader audience than her firebrand father and party founder Jean-Marie Le Pen, who has been convicted of racism or anti-Semitism on a number of occasions.
A French court earlier this month upheld a three-month suspended jail sentence against him for calling the Nazi occupation of France "not especially inhumane".
Marine Le Pen said the couple had been told by police that the attackers were football fans who were likely part of a radical and sometimes violent group that supported Paris Saint-Germain soccer team.
But Montebourg quickly rejected her claim.
"They were obviously National Front political activists because they were shouting 'Blue, White, Red' (the colours of the French flag) 'France for the French!' 'Le Pen for president!'," he said.
Francois Hollande, the Socialist presidential candidate, joined politicians from across the spectrum to condemn the attack on Pulvar and Montebourg, who stood against him in a party primary last year to pick a contender for the presidential vote.
"It is unacceptable to attack a person for his ideas and to do it in a cowardly manner with shouts, insults, with glasses thrown and with remarks that border on anti-Semitism and racism," he said.
Le Pen, whose party plays on fears of growing Muslim influence in France, stirred controversy last week when she claimed that all meat sold in the Paris region was prepared using Islamic halal traditions.
An opinion poll published Tuesday by IFOP said Hollande would take 28.5 percent of the vote in the first round of the presidential election in late April, against 27 percent for President Nicolas Sarkozy.
Le Pen would come in third in the first round with 17 percent, it said.