France wants to gradually phase out the use of diesel fuel for passenger cars and will put in place a system to identify the most polluting vehicles, Prime Minister Manuel Valls said.

Next year, the government will launch a car identification system that will rank vehicles by the amount of pollution they emit, Valls said. This will make it possible for local authorities to limit city access for the dirtiest cars.

“In France, we have long favored the diesel engine. This was a mistake, and we will progressively undo that, intelligently and pragmatically,” Valls said.

About 80 percent of French motorists drive diesel-powered cars.

Taxation would have to orient citizens towards more ecological choices, Valls said in a speech on Friday. The 2015 state budget measures would seek to reduce the tax advantage of diesel fuel versus gas.

The government has announced it will raise the so-called TICPE excise tax on diesel by €2 cents per liter, bringing in €807 million to state coffers in 2015.

Valls also said the government was working on plans to widen the number of beneficiaries of a subsidy for the conversion of old diesel engines in areas with anti-pollution plans.

Energy Minister Segolene Royal announced earlier this year that drivers scrapping diesel-powered cars to buy an electric one would be entitled to a bonus of up to €10,000 ($13,500).