Hundreds of people including sex workers protested in Paris on Saturday against plans to make soliciting prostitution illegal, criticising a minister's drive to eradicate the practice of paying for sex as counter-productive.

France's minister for women's rights, Najat Vallaud-Belkacem, caused a stir in late June by saying she would seek to make prostitution disappear by punishing those who pay for sex, rather than the prostitutes themselves.

The Socialist politician was backed by prominent feminists and allies in government, but her remarks unleashed a hail of criticism from sex workers' unions, which argued that punishing clients would drive business underground, thereby endangering prostitutes.

At Place Pigalle in the heart of Paris' red-light district, dozens of sex workers chanted pro-prostitution slogans through loudspeakers and waved signs that read "Penalised clients = murdered prostitutes" and "Sex work is work too".

In France, with an estimated 18,000 to 20,000 prostitutes according to a 2012 report, prostitution is not illegal, although laws exist against pimping, human trafficking and soliciting sex in public.