Cassandre Fristot, 34, was seen at the protest on Saturday in the eastern city of Metz holding a sign denouncing President Emmanuel Macron’s enforcement of a health pass in France to encourage people to get vaccinated.

The sign contained the names of several prominent politicians, businessmen and intellectuals in France, most of them Jewish, and police said it “had a message that was manifestly ant-Semitic”.

Fristot, a former local councillor for the far-right National Rally (RN), was detained on Monday and her home searched. Metz prosecutor Christian Mercuri said her trial would start on September 8th. If convicted, she risks up to one year in prison and a €45,000 fine.

Interior Minister Gérald Darmanin had on Monday shared the image of Fristot brandishing the sign on his Twitter account, describing it as “despicable” and then announcing she had been arrested.

“Anti-Semitism is a crime, not an opinion. Such words will not go unpunished,” he said.

About 237,000 people protested across France on Saturday against the Covid health pass which critics say encroaches on civil liberties. Macron has retorted that people are neglecting their duty as citizens if they fail to get vaccinated.