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PARIS — French far-right party leader Marine Le Pen will go on trial for comparing Muslim street prayers to wartime Nazi occupation, party officials and the prosecutor's office said on Tuesday.

Le Pen, whom polls see likely to win a regional election in northern France in December, has widened the National Front's appeal since she took its helm in 2011 by expelling extremists and cracking down on anti-Semitism.

France's far-right National Front political party leader Marine Le Pen. PASCAL ROSSIGNOL / Reuters

But the party also thrives on concerns over immigration and radical Islam. In a meeting in 2010, Le Pen criticized Muslims praying in the streets when mosques are full.

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She will be judged on Oct. 20 over charges of "incitement to discrimination over people's religious beliefs," the prosecutor's office in Lyon said.

Le Pen had told the 2010 rally in Lyon: "I'm sorry, but for those who really like to talk about World War Two, if we're talking about occupation, we could talk about that (street prayers), because that is clearly an occupation of the territory."

"It is an occupation of sections of the territory, of neighborhoods in which religious law applies, it is an occupation. There are no tanks, there are no soldiers, but it is an occupation anyhow, and it weighs on people," she added.

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She reacted indignantly on Tuesday to news of the trial." It is a scandal that a political leader can be sued for expressing her beliefs," she told Reuters. "Those who denounce the illegal behaviour of fundamentalists are more likely to be sued than the fundamentalists who behave illegally."

It was not immediately clear whether the trial, which will take place less than two months before the December regional election, could harm Le Pen's chances of winning over the Nord-Pas-de-Calais region.

Her opinion poll ratings have not suffered from a row with her father Jean-Marie, the FN founder, whom she expelled from the party in August for comments playing down the Holocaust.