Currently, people on short-term contracts, whether a hairdresser or a theater worker whose play has ended, can receive unemployment benefits for a period equivalent to the number of months worked. Other workers who have held a job for five or more years can get benefits for up to two years (or three years for those over 55).

Under Mr. Macron’s plan, people will need to have worked for six of the last 24 months to qualify for unemployment benefits. For those earning in the top 10 percent, who can get up to 7,700 euros (about $8,700) a month in benefits, the payments will drop by 30 percent after six months.

A previously passed measure will cap benefits for job seekers who reject more than two “reasonable” job offers, even if they are overqualified for the positions.

“The idea is to change the rules so that working always pays more than not working,” Prime Minister Édouard Philippe told lawmakers last month.

The government expects that the program will save €3.4 billion, or about $3.9 billion, and get up to 250,000 people off the unemployment rolls — helping Mr. Macron achieve a campaign pledge of lowering unemployment to 7 percent by the next presidential election in 2021.

But economists say the pay difference in many cases won’t be enough to encourage people to take jobs available through France’s unemployment offices, which tend to pay close to the gross monthly minimum wage of €1,521. France’s unemployed receive an average of €1,000 a month.

And short-term contracts that throw people back into unemployment may still abound, despite the higher payroll tax. The tax would apply to seven sectors, including restaurants, hotels and transportation, in hopes of getting companies to switch to permanent contracts. But some industries that are rife with temporary contracts, including construction, will be exempt.