PARIS -- The horrors of the World War II Nazi death camps moved front and centre in France's presidential campaign on Friday, nine days before the election, reawakening the anti-Semitic stigma that has clung to the party of far-right candidate Marine Le Pen and that she has spent more than six years trying to erase.

Transforming the National Front into a voter-friendly party without compromising its anti-system essence -- which is her banner -- has been perhaps her toughest battle preparing for her dream job as chief of state.

Her efforts, that included showing her father, party founder Jean-Marie Le Pen, the door in 2015, took a hit after remarks questioning the Holocaust allegedly made in 2000 by the man chosen to temporarily replace her as party chief surfaced in the French press. The reports threatened to undo her work nudging the National Front from pariah status to respectability.

Le Pen -- who once called Nazi death camps the "height of barbary" -- firmly denied that anyone in the party leadership would cast doubt on the extermination of six million Jews and others, some deported from France.

"Let things be very clear. I abhor these theories," she said in an interview on BFM-TV.

"There is no one in the leadership of the National Front who defends this kind of thesis," she said.

Even without the cloud of anti-Semitism casting its shadow anew on the party, Le Pen, who took over the National Front in 2011, faces claims of racism for evoking fears that Muslims want to conquer France. A resistance was mounting with anti-Le Pen demonstrations planned.

But it was the alleged remarks 17 years ago of Jean-Francois Jalkh, a discrete party vice-president and longtime member, which raised the question of whether Le Pen risks throttling France backward to its darkest moments if she defeats centrist rival Emmanuel Macron, who is favoured, and becomes the next president.

Jalkh firmly denies French media reports that he questioned whether Zyklon B poison gas was used in death camps. Lawyer David Dassa-Le Deist said he was filing a defamation suit against Le Monde newspaper, which identified his client as a negationist, someone who denies the Holocaust.

Damage control was swift. Another party stalwart, Steeve Briois, mayor of Le Pen's northern bastion, Henin-Beaumont, was named to replace Jalkh as temporary party chief while Le Pen campaigns in the critical final stretch ahead of the May 7 vote.

Le Pen has reversed the party's slide into ideological darkness, after a purge of the old guard, including their master, Le Pen senior, when he repeating a statement belittling the Holocaust for which he was convicted. But she has not fully succeeded in revamping the party's image.

In the 1990s, 70 per cent of the French said the National Front was a danger to democracy -- a figure that today has fallen to 58 per cent, according to noted far-right expert Jean-Yves Camus.

Surmounting that stigma is critical for Le Pen to obtain a majority in the final-round vote and surpass her rival, independent centrist Emmanuel Macron, a former economy minister and banker favoured to win -- and the rival Le Pen reviles as the symbol of an elitist system she rejects.

"No, the National Front is not a party like any other," Macron said in the town of Chatellerault. Fellow politicians who refuse to call on voters to block Le Pen "are making a deep, serious, moral and political mistake," he said.

For Macron, the timing was perfect. He paid a visit to Oradour-Sur-Glane, the village that has stood still in time since the 1944 Nazi massacre of 642 of its inhabitants.

Oradour-Sur-Glane, with the savagery of a massacre, is a macabre, black-and-white showcase of the Nazi occupation of France.

French emotions around France's history of collaborating with the Nazis remain complex seven decades after the war's end. The country has never undergone a national atonement. In 1995, President Jacques Chirac boldly declared that the collaborationist Vichy regime -- which helped in the deportation of 75,000 French Jews -- was the French state. However, many still view the actions of Vichy as a historical anomaly. Some still salute its leader, Philippe Petain, a hero of World War I.

The scandal over alleged remarks by a party vice-president was the second time this month that Le Pen has been cornered by France's World War II past.

The populist candidate said April 10 that France was not responsible for the roundup of Jews during World War II. She said she "considers that France and the Republic were in London" during the war, with Gen. Charles de Gaulle who oversaw the Resistance.

Famed Nazi hunter Serge Klarsfeld called her position a "re-alignment" with her father.

Even if she is widely thought to have erased anti-Semitic sentiment from the party, Le Pen is taken to task about her attitude toward Muslims and her anti-immigration platform which would include a moratorium on immigration, a 10,000-person lid on new arrivals and a street ban on Muslim headscarves and Jewish kippahs.

A battery of culture groups representing jazz artists, choreographers or cinema called for a rally next Monday. The leading anti-racism group, SOS Racism, and Jewish groups plan a concert two days later. Yves Jean, president of the University of Poitiers in western France, is rallying students to vote against Le Pen.

Le Pen, meanwhile, called on followers of unsuccessful far-left candidate Jean-Luc Melenchon to back her and she gained one important backer Friday, a conservative candidate also eliminated from the race, Nicolas Dupont-Aignan. However, vice-president of his party, former director of the national library, Dominique Jamet, was leaving in protest.

------

Sylvie Corbet contributed from Chatellerault, Angela Charlton contributed from Paris.