Courts will also have the power to order those convicted to attend a "prostitution awareness programme", similar to programmes on alcohol abuse for drunk drivers.
The bill includes financial help of several hundred euros to help wean prostitutes off sex work.
The proposed law - a campaign promise by President Francois Hollande - has been inspired by Scandinavia, where several countries once tolerant of prostitution are now striving to wipe it out, saying it is demeaning, exploitative and dominated by pimps.
But the bill has ignited a storm within France's political and intellectual elite and down on the street.
The monthly magazine Causeur issued a petition slamming the bill under the title "Don't Touch My Whore!"
Signatories of the "343 Bastards' Manifesto"(Manifeste 343 Salauds) included writer and philosopher Pascal Bruckner, author and critic Frederic Beigbeder and lawyer Richard Malka.
"We consider that everyone has the right to freely sell their charms - and even to like doing so ... We do not want lawmakers to adopt rules governing our desires and pleasures," they said.
"And when Parliament gets involved in drawing up rules on sexuality, everyone's freedom is threatened."
The appeal took a double swing at cherished moments in Socialist history. In 1971, 343 women, in an appeal to legalise abortion, openly admitted they had had an illegal pregnancy termination. They later became dubbed the "343 Sluts" (salopes) by the satirical magazine Charlie Hebdo.
And the petition's "Don't Touch My Whore" is a mashup of a 1985 anti-racist campaign in 1985, "Don't Touch My Pal", run by Harlem Desir - now the Socialist Party's chairman.
Najat Vallaud-Belkacem, the Minister for Women's Rights, reacted bitterly.
The 1971 signatories "demanded to be able to freely decide what to do with their own bodies", the minister said.
"The 343 Bastards are demanding the right to decide what to do with the bodies of other people."
Twelve leading politicians have ridden to the Government's help, issuing a call for national unity on the plan. They include Socialists and a communist, as well as former conservative ministers Roselyne Bachelot and Chantal Jouanno and former Greens minister Dominique Voynet.
But not everyone on Paris' trendy Left Bank is in favour.
Among the dissenters are Segolene Royal, President Francois Hollande's former partner and mother of their four children, who says the law is sapping the drive against unemployment.
Doubters include a group of prominent intellectuals, among them feminist Elisabeth Badinter and erotic literature author Regine Desforges.
"A woman who prostitutes herself, whether she does so occasionally or full-time, is not necessarily a victim of male oppression," the intellectuals cautioned. "And clients are not all horrible predators or sexual obsessives who treat the woman as disposable objects."
France has a long history of tolerance towards the sex industry.
In the 14th century, many towns had a brothel, or "maison close", where a red lantern hung outside the door.
It was often operated by a member of the clergy - usually an abbess - who paid rent to the local authorities.
Authorised brothels, where prostitutes had to have health checks, existed until 1946, when they were closed under an abolitionist mood that gained ground after World War II.
Grassroots associations in France say the planned law is likely to drive the sex industry underground, to the detriment of those who work in it.
The charity Medecins du Monde (Doctors of the World) branded it as a "social regression ... deceitful, dangerous and ineffective".
"Prostitutes will become more isolated in their work. They will have to use isolated roads, carparks, public gardens," a group called the Sex Workers' Union, or STRASS, told the Weekend Herald.
"They will be pushed from one place to another to another by the police. It will be totally disastrous," said their spokeswoman, Manon, a Parisian prostitute who contacts her clients through the internet.
"At the moment, we have a good relationship with the police, and if we have a problem with violence they take us seriously.
"If the government wants to protect the prostitutes, then they should be proposing to help them carry on their work."
Europe's answers
France's planned crackdown takes place in a wider context in Europe, where many cities are shocked by a rise of visible prostitution, including women from eastern Europe and Africa who are de facto slaves of pimps and traffickers.
Countries have tried to deal with the problem in varying ways.
Leading the battle for abolition is Sweden, where prostitution is considered a social problem and a sign of gender inequality.
In 1999, it introduced a law making it illegal to buy sex. Norway followed suit in 2008.
In Iceland the law prohibits earning a living from prostitution.
But Denmark decriminalised prostitution in 1999. In Germany, it was legalised 10 years ago; this year, its Parliament approved tougher regulation of brothels and stricter punishments for human trafficking.
In Switzerland, prostitution is legal above the age of 18 - recently increased from 16. Sex workers can ply their trade as long as they pay taxes and social charges. The ultra-conservative banking city of Zurich this year even opened the world's first sex "drive-in," aimed at providing a safer environment for prostitutes.
