Founder of France's far-right National Front to go on trial for April assertion that Nazi gas chambers were just a 'detail' of World War II.

The founder of France's far-right National Front party, Jean-Marie Le Pen, will be charged with denying the Holocaust for saying Nazi gas chambers were a "detail" of World War II.

Le Pen, 87, was summoned to stand trial before a Paris court several weeks ago, though a trial date has not yet been set, sources close to the investigation told AFP on Friday.

Infuriated by the charges, Le Pen reportedly said, "I thought that millions of French people had marched for freedom of expression,” referencing demonstrations that occurred in the wake of the shooting at the Charlie Hebdo magazine in January.

“I thought that included the right to blaspheme. And this is blasphemy, isn’t it? It is after all an almost religious point,” he added, according to The Independent.

Speaking to BFMTV in April, Le Pen asserted that "gas chambers were a detail of the war, unless we accept that the war is a detail of the gas chambers."

Le Pen first called the gas chambers a "detail" of World War II in 1987, repeating it 10 years later in Munich, Germany. He made similar comments to a French magazine in 2008 and a year later at the European Parliament.

His most recent statement sparked outrage among Jewish groups and anti-racism campaigners, with activist group SOS Racisme pledging to see that Le Pen was "again convicted" for his words.

The remarks also created a public row between Le Pen and his daughter, Marine Le Pen, who, since taking over National Front in 201,1 has sought to distance the far-right party from its anti-Semitic roots and turn it into more palatable alternative to mainstream voters.