Bruno Jeanbart, of the OpinionWay polling institute, said Le Pen had taken a "risk" because the remarks could associate her with her father, even though they "were not ambiguous".
Le Pen said Sunday on RTL radio "I don't think France is responsible for the Vel d'Hiv", in reference to the stadium where many thousands of Jews were rounded up on July 16 and 17, 1942, before being sent to Nazi death camps.
Le Pen has said repeatedly that France would leave the European Union under her leadership, while Melenchon has said he would pull the country out of North Atlantic Treaty Organisation. "It's not France", she told LCI television.
Speaking at a big rally in the southern port city of Marseille, veteran Communist-backed candidate Melenchon sounded full of confidence.
The French government has previously apologized for the role French authorities played in the round-up of 13,000 Jews at the Vel d'Hiv cycling track in 1942 at the behest of Nazi officers.
NATO says trans-atlantic bond 'rock solid' as Tillerson visits
Meanwhile, Nato secretary general Jens Stoltenberg said that ties between European Nato members and the United State s were "rock solid".
Le Pen later said in a statement she "considers that France and the Republic were in London" during wartime and "the Vichy regime wasn't France".
"The Vichy regime was not France", she said, adding however that this did not absolve those who participated in "the vile roundup of Vel d'Hiv and all the atrocities committed during that period".
Rival election candidates also criticized Le Pen.
French physicist Serge Galam, who predicted a Trump victory, claims that a Le Pen presidency is very likely because of her strong base of support versus lukewarm feelings that exist for the other potential runoff candidates. "It ... runs completely counter to the party's efforts and gives ammunition to all those who say that the National Front remains a party with extreme right militants and culture".
In 1995, more than 50 years after the fact, then president Jacques Chirac deemed that "the time had come to clearly recognise the fault of the collaborating French state, and no (subsequent leader) should contest it", Le Monde said.
2 more officers placed on leave after passenger dragged off United flight
Predictably, it did not take much digging to find that festering frustration extended beyond members of my flight crew. On Thursday, the Chicago's aviation commissioner is expected to address a city council committee about the incident.
Meanwhile, two of the outside contenders in France's presidential election, Francois Fillon and Jean-Luc Melenchon, whipped up support with mass rallies on Sunday, seeking a last-gasp boost ahead of an increasingly tight first voting round.
Of the rest of the candidates, the socialist Benoit Hamon experienced in recent days a notable setback and is below 10 percent, which leaves him practically out of the fight. The two-round presidential election is set for April 23 and May 7.
French presidential candidate Emmanuel Macron wants to hold discussions with USA social media groups about how to halt the spread of "Islamist propaganda".
Le Pen and Macron - dubbed the "fragile favourite" by the Journal de Dimanche - are neck-and neck but both have lost ground slightly and would win 23-24 per cent if the vote were held today. In this framework, she said French Jews should be banned from wearing kippahs in some public spheres to preserve equality and facilitate further bans on wearing Muslim religious clothing.
She's only 5, but Beckham daughter gets brand protection
David and Vicky's daughter is too young to think about her own business but Victoria has registered Harper seven Beckham's name. The move means Victoria has the rights to use Harper's name on products such as aromatherapy oils and anti-wrinkle cream.