French National Rally leader Marine Le Pen has been barred from running for public office for five years.
Le Pen, who left court before the verdict was read out, was found guilty in an embezzlement case.
She was also given a four-year jail sentence, with two years suspended. It is unclear if she will serve any jail time.
The ban will derail her hopes of running for the presidential election in 2027.
The far-right leader and 24 other officials from her National Rally party were accused of diverting more than €3m (£2.51m) of European Parliament funds to pay France-based staff between 2004 and 2016.
The judge also handed down guilty verdicts to eight other current or former members of Le Pen’s party who, like her, previously served as MEPs in the European Parliament.
Sitting in the front row in the court in Paris, Le Pen showed no immediate reaction as the chief judge read the verdict.
Judge Benedicte de Perthuis ruled: “It was established that all these people were actually working for the party, that their (EU) lawmaker had not given them any tasks.
“The investigations also showed that these were not administrative errors … but embezzlement within the framework of a system put in place to reduce the party’s costs.”
Le Pen denied accusations she was at the head of “a system” meant to siphon off EU funds to benefit her party.
The defendants denied any wrongdoing and claimed the money was used legitimately.
The nine-week trial took place at the end of last year.
The 56-year-old is a three-time presidential contender who has said 2027 would be her final run for top office.
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