Far-right leader Jean-Marie Le Pen sparked a chorus of outrage in France on Friday by repeating an incendiary claim that the Nazi gas chambers were a "detail of history."
Anti-racism and Jewish groups threatened immediate legal action against the National Front chief - who already holds several similar convictions - after he made the comments in a magazine interview.
"I said the gas chambers were a detail of the history of World War II: that, to me, seems so obvious," the 79-year-old Le Pen told Bretons magazine.
Le Pen was fined 1.2 million francs ($290,000) for making the initial remarks in a radio interview in 1987.
When the Bretons journalist told him that the Nazis "deported people to camps simply to kill them," Le Pen replied: "But that is what you believe. I don't feel obliged to adhere to that view."
"I observe that in Auschwitz there was the IG Farben factory, there were 80,000 laborers working there. As far as I know they were not gassed, anyway, nor burned."
The French Council of Jewish Institutions (CRIF) accused Le Pen, whose political fortunes have recently slumped, of "going even further down the road of revisionism... to draw attention to himself."
SOS racism called his remarks "a pitiful attempt to keep himself in the media eye", while the French Jewish Student Union (UEJF) said it was taking legal action against him.
The International League Against racism and anti-Semitism (LICRA) said it planned to file fresh legal action aginst Le Pen after consulting its lawyers.
And France's Young Socialist Movement (MJS) said it hoped "the courts will not let such remarks go unpunished."
Convicted several times for inflammatory comments on race and World War II history, Le Pen was handed a three-month suspended jail sentence in February for describing the Nazi occupation of France as "not especially inhumane".
He was found guilty of denying a crime against humanity and complicity in condoning war crimes, over the remarks made in an interview with a far-right magazine in 2005.
In 2002 the firebrand leader shocked Europe by making it through to the second round of France's presidential election.
But his party has racked up millions of euros of debts after losing state subsidies thanks to its unexpectedly poor showing in last year's parliamentary elections