French prosecutors filed preliminary charges against Marine Le Pen on Thursday, accusing him of posting brutal images of Islamic State violence on Twitter.
The prosecutor's office in the Paris suburb of Nantes said the allegations were intended to "spread images of violence ".
"If the case is finally tried and she is convicted, Le Pen will face up to three years in prison and 75,000-euro ($90,000)fine.
A tweet from Le Pen on December 2015 showed that Islamic State extremists, including American journalist James Foley, were executed.
She released the news after the IS attack in Paris in November 2015, accusing the government of not doing enough to protect France.
Le Pen told bfm TV on Thursday, "it was clearly meant to keep me quiet.
But I will not be suppressed ".
Le Pen said she would see this underlying belief as a "medal for patriotism and defending the French people ".