Presidential front-runner Royal backs gay marriage

She told Têtu, the leading gay and lesbian magazine, that "opening up marriage to same-sex couples is needed in the name of equality, visibility and respect". She said that she also supported gay adoption.

According to a recent poll, 60 per cent of the French support gay marriage, which is legal in countries such as the Netherlands, Belgium and Spain.

Ms Royal, who has four children with her partner, François Hollande, who heads the Socialist Party, argued that "whether the parents are homosexual or heterosexual, adoption is above all a family project".

Her comments, published before today's Gay Pride event, which is expected to draw half a million people, were welcomed by leaders of the French gay community. Her stand, described as a "conversion" by the daily newspaper Libération, took French public opinion by surprise. Ms Royal, 52, has issued some tough statements recently on law and order, and has often been criticised for her conservative positions. Only two years ago, she had been more reticent about the divisive issue of gay marriage.

But after the Socialist Party adopted a platform that includes gay marriage and adoption, Ms Royal had no choice but to stick to the party line.

Even though her approval rating keeps on rising, she still needs to fight to win the Socialist nomination in November for the presidential candidacy in a party where most leaders resent her for stealing the limelight.