The spat between one of France's most famous actresses and its first lady came as the Vatican announced it was interceding with Tehran for the life of Sakineh Mohammadi Ashtiani, a 43-year-old mother of two.
Mrs Bruni-Sarkozy signed an open letter in support of Mrs Ashtiani.
That prompted an Iranian newspaper to label her a "marriage wrecking prostitute" last week because of her previous affairs with high-profile celebrities who already had partners.
"When you are a famous person you need to be more cautious when you lend your support to causes – with her past she should have been more careful. It can be a double-edged sword," Miss Deneuve said. >>> Nick Pisa in Rome | Sunday, September 05, 2010