French film legend-turned-activist Brigitte Bardot took a swipe at Sarah Palin on Tuesday, saying the US vice-presidential candidate was a disgrace to women.

"I hope you lose these elections because that would be a victory for the world," Bardot wrote in an open letter to Republican John McCain's running mate in the November vote.

"By denying the responsibility of man in global warming, by advocating gun rights and making statements that are disconcertingly stupid, you are a disgrace to women and you alone represent a terrible threat, a true environmental catastrophe," wrote Bardot.