The sentence made the far-right leader ineligible for five years, excluding her from the 2027 election unless she can win an appeal.
Marine Le Pen, the French far-right leader, was found guilty of embezzlement by a criminal court in Paris on Monday and immediately barred from running for public office for five years, setting off a democratic crisis in France.
The verdict effectively barred the current front-runner in the 2027 presidential election from participating in it, an extraordinary step but one the presiding judge said was necessary because nobody is entitled to “immunity in violation of the rule of law.”
Jordan Bardella, Ms. Le Pen’s protégé and a likely presidential candidate in her absence, said on social media, “Not only has Marine Le Pen been unjustly convicted, French democracy has been executed.” Hard-right leaders across Europe, including Viktor Orban, the Hungarian prime minister, appeared to agree.
“Je suis Marine!” Mr. Orban declared.
However, Sacha Houlié, a centrist lawmaker, asked, “Is our society really so sick that we are going to take offense at what is no more and no less than the rule of law?”
The verdict infuriated Ms. Le Pen, an anti-immigrant, nationalist politician who has already mounted three failed presidential bids. Looking grim and murmuring “incredible,” she walked briskly out of the courtroom before the judges had completed reading her sentence.
She did not address the dozens of camera crews outside the courtroom, but she was expected to speak on French television on Monday evening. She had spoken of her “serenity” before the hearing but there was little evidence of that.
