The 42-year-old actress, star of 2006's 'Casino Royale', was set to star in a sci-fi film - 'A Patriot' - before production was halted in October 2019.
She is suing the production company, White Lantern Films, to obtain, despite the cancellation of the project, her stamp of one million dollars (918,000 euros).
But the British production company decided to counterattack by launching its own lawsuits against the actress, believing that she had harmed the production of the film.
The trial which opened on Thursday is expected to last nine days.
Called to the stand on Monday, black turtleneck and dark green blazer, Eva Green reaffirmed that she had first "fallen in love" with the film project which was to deal with the climate crisis.
Lawyers for White Lantern Films believe, however, that the French actress expressed "lack of confidence and dissatisfaction" with members of the production team.
They rely on WhatsApp messages in which Eva Green allegedly called a member of the team "evil", "sneaky sociopath", "liar and crazy".
She also reportedly called production manager Terry Bird a "moron" and "a finished asshole."
Asked about the fact that she would have qualified in a message to her agent as “weak” and “stupid” producer Adam Merrifield and screenwriter Dan Pringle, Eva Green replied that she could have made insulting remarks under the influence of emotion , apologizing for his "inappropriate remarks".
French actress Eva Green arrives at court on January 30, 2023 in London © Daniel LEAL / AFP
"I don't know (...) it's my French side that sometimes comes out," she said.
"Sometimes I say things out of emotion that I don't really mean. Of course they're not weak or stupid."
"I don't care about the money. I live to make good films, it's my religion", she added, stressing that she worried as the filming progressed that the film would be bad. and harming his career.
© 2023 AFP