France's richest woman, Liliane Bettencourt, has filed a suit accusing her daughter of "abuse", in the latest of a series of family disputes.
Lawyers for the L'Oreal heiress said Francoise Meyers-Bettencourt's attempt to have her mother declared mentally unsound amounted to "moral violence".
Liliane Bettencourt's fortune is the focus of several judicial inquiries.
One involves allegations of illegal donations to Nicolas Sarkozy's presidential campaign in 2007.
In September, police searched the main offices of his political party in response to claims made by the 87-year-old heiress's former butler.
Earlier this month, her estranged daughter attempted for a third time to have her mother made a ward of court.
In a statement, Liliane Bettencourt's lawyers said the repeated demands "amount to a psychological violence".
Ms Meyers-Bettencourt claims that people close to her mother have taken advantage of her and that she is mentally unfit to look after her fortune.
Liliane Bettencourt, whose father founded the L'Oreal cosmetics company, is believed to have given celebrity photographer Francois-Marie Banier about 1bn euros of gifts over a 20-year period.
According to Forbes magazine, her fortune is estimated at $20bn (£12bn, 14bn euros).