Far-right leader Marine Le Pen has been charged by a French judge for tweeting gruesome images of purported atrocities by Islamic State (IS).
Beyond the three-years in prison, prosecutors can also demand a maximum fine equivalent to £67,000.
The IS group claimed resonsiblity for those and several other attacks in France since January 2015.
After the investigation was announced on Thursday, Ms Le Pen defended her actions, saying she was being charged for condemning IS.
The investigation relates to three graphic images of Islamic State executions she posted on Twitter in December 2015, including the beheading of American journalist James Foley.
The indictment comes after the National Assembly voted in November to strip the National Front (FN) president of her parliamentary immunity from prosecution for tweeting three photographs showing killings by IS. One image showed the decapitated body of Foley, the BBC reports.
The prosecutor in the Paris suburb of Nanterre lodged a preliminary charge against the National Front leader for circulating "violent messages that incite terrorism" on Thursday (1 March). The others showed a man in an orange jumpsuit being driven over by a tank and another man being burned alive in a cage.
John and Diane Foley accused Ms Le Pen of using the "shamefully uncensored" photos for her own political ends. Liberal candidate Emmanuel Macron is facing far-right candidate Marine Le Pen in an election that has sewn sharp divisions in France.
The charges come as Le Pen's party is in crisis after she lost her presidential bid previous year.
Le Pen was a presidential candidate in France's election previous year, but lost to Emmanuel Macron.
She has recently sought a political rebound, calling for a rebranding of the National Front in order to "forge alliances" and "take power".
"I know many people are attached to the National Front name", she told 400 party members.