A draft law accepted in principle by ministers yesterday, would also force the parties to present lists equally divided between men and women for the municipal elections in 2001. If the law is approved by parliament, it would give the male-dominated world of French politics the most rigid system of gender quotas in Europe.
Right-of-centre opposition parties detest the proposals. Opposition will be led by, among others, Michele Alliot-Marie, who was elected president of the neo-Gaullist RPR at the weekend. Ms Alliot-Marie, the first woman to lead a major French political party, describes the quota idea as "insulting". She points to her own success as proof that women can break through the gender barrier. Statistics, however, bracket France - and the RPR especially - among the most macho European Union states.
Ms Alliot-Marie is one of only seven women among the 130 RPR members of the National Assembly. Just over 10 per cent of French deputies are women, compared with 18.4 per cent of MPs in Britain and 42.7 per cent in Sweden.
The quota proposals will go before the National Assembly in January. Lists for local elections would only be accepted if they consisted half of men and half of women. Critics point out that, in practice, men could still hog the higher, electable, places on the lists. The Socialists have promised to alternate the names of men and women, but this would be voluntary.
Parliamentary elections in France operate on a constituency system, with no lists. Under the proposed law, parties which failed to field roughly equal numbers of men and women across the country would have part of their state-paid election expenses confiscated, on a sliding scale according to the size of their electoral gender gap.
The idea has been strongly pushed by the Prime Minister, Lionel Jospin, who imposed a gender balance on his own Socialist Party's candidates at the last national and European elections. His proposal has, however, many critics on the left as well as the right. Some Socialists complain that there are not enough women willing and qualified to stand for office to fill a 50 per cent quota. The result, they say, is that women are being pushed into standing as "puppets" for men.
The example is given of the 20th arrondissement of Paris. In 1997, the sitting MP, Michel Charzat, was forced to give way to a woman under the party's voluntary quota rules. The successful candidate, Veronique Carrion Bastok, was the wife of Mr Charzat's most senior aide. She resigned in September and was replaced in a by-election last weekend - by Mr Charzat.
Another socialist deputy in Paris commented to the newspaper Liberation: "Parity [between men and woman] has generated a new form of male domination, which says: `I am in favour of women as long as I can decide which women'."
Supporters of the law say that these are isolated cases, which prove just how much French politics needs to have its windows opened by a new generation of female politicians. In the centre-right parties, they say, legally enforceable quotas are the only way to break down the barriers which often restrict the role of women to licking stamps and adorning political platforms.