French prostitutes have staged a protest outside parliament in Paris against a new crime bill which they say threatens their livelihood.

The bill has been approved by cabinet, but not yet by parliament

About 500 women and men, some wearing masks and waving banners, took part in the demonstration, which activists said was part of the profession's biggest protest movement in the city since 1975.

"You sleep with us, you vote against us," read one banner.

The French Government plans to place a wide-ranging bill before parliament which would include a law making "passive soliciting" - touting for sex by any means, including by use of dress or posture - a criminal offence.

Prostitutes say the law would prevent them from earning income and expose them to dangers from unscrupulous customers or pimps.

"They are trying to make us out to be delinquents, even criminals," one prostitute told French news agency AFP.

'Repression' claims

The bill, drawn up by French Interior Minister Nicolas Sarkozy, increases police powers, tightens gun laws and includes penalties for begging and loitering.

It is a law that is repressive in every respect... it won't solve the problem, it'll just hide it

Women's rights activist Josiane Ceret

He said the law was necessary to "guarantee the security of the French people".

It was approved by the cabinet in October but has yet to be passed by parliament.

Prostitution is legal in France and at the moment the country's estimated 18,000 prostitutes can only be fined if their activities disturb the peace.

But under the proposed law, prostitutes could face six months in prison or a fine of up to $7,500 if convicted under the law.

"It is a law that is repressive in every respect," activist Josiane Ceret, from France's Women's Rights Collective told the Associated Press news agency.

"It won't solve the problem, it will just hide it."

The Paris protest follows similar demonstrations in Marseilles and Lyon.