The first transgender woman to be awarded Best Actress at the Cannes Film Festival on Wednesday filed a legal complaint over a “sexist insult” from a far-right politician after her win.

Karla Sofia Gascon and co-stars jointly received the accolade on Saturday for their performances in French auteur Jacques Audiard’s dazzling narco musical Emilia Perez.

In the film, the 52-year-old Spanish actor – who lived as a man until she was 46 – plays a Mexican drug trafficker both before and after gender reassignment surgery.

French far-right politician Marion Marechal after her win posted on X: “So a man has won Best Actress. Progress for the left means the erasure of women and mothers.”

Gascon, through her lawyer, told AFP: “We need to stop such comments.”

Her lawyer Etienne Deshoulieres said she had filed a legal complaint for “sexist insult on the basis of gender identity”.

Gascon, who has a wife and daughter, dedicated her win in Cannes to “all the trans people who are suffering”.

Earlier during the festival, she urged others to stop labelling people like her.

“Being trans is unimportant. A trans person is someone going through a transition. Once they have transitioned, that’s it. They are what they are,” she said.

Emilia Perez earned particular praise from critics for not fixating on the gender transition, but moving beyond to explore themes of family, love and the victims of Mexico’s gang violence.