The bill, which the government says is aimed at preventing violence against women, has come under fire from celebrities like Catherine Deneuve and Charles Aznavour, leading intellectuals and prostitutes themselves.
Spearheaded by Women's Rights Minister Najat Vallaud-Belkacem, the law will fine clients of prostitutes USD 2,025 for a first offence and double that for repeat offenders.
Prostitution itself is legal in France but soliciting, pimping and minors selling sex are prohibited. The government estimates about 20,000 prostitutes operate in France.
Several hundred prostitutes marched through the streets of Paris to denounce the plan last month, waving placards reading, "Punishing Clients = Killing Prostitutes" and "We're Whores and We're Proud!"
Sex workers' group Strass argues the measure will hurt prostitutes by driving the practice further underground.
"Punishing clients is a harmful measure that puts the health, security and lives (of prostitutes) in danger," it said.
Supporters of the bill -- which could be debated from as early as Wednesday -- point out that it also proposes a series of measures to assist prostitutes, especially those trafficked to France, including easier access to working papers, housing and financial support.
But opponents say its punitive nature is a step too far and intrudes on the private lives of French citizens.
In a series of open letters, celebrities and cultural figures have urged the government to reconsider the plan.
About 60 people, including Deneuve, Aznavour and former culture minister Jack Lang released an open letter this month opposing the bill and calling for "a real debate" on prostitution "without ideological prejudice".
Another more contentious letter released last month told lawmakers "Don't touch my whore!", saying: "When parliament gets involved in adopting rules on sexuality, everyone's freedom is threatened."
The letter was controversially dubbed the "Manifesto of 343 Bastards", echoing another text published in 1971 by 343 women declaring they had an abortion when it was still illegal.
Surprising some, among the most vocal opponents of the bill has been the philosopher and feminist Elisabeth Badinter, who has pleaded that "the state has no place legislating on individual sexual activity."
Badinter said she saw no direct link between male sexuality and violence against women, accusing some of having "a stereotypical view that is very negative and moralistic and which I reject."