France could start to phase out diesel-engined passenger cars as it rolls out a programme to identify the most polluting vehicles on its roads.

Prime minister Manuel Valls said the government will put in place a system to identify the most polluting vehicles that will rank cars by the amount of pollution they emit.

This will make it possible for local authorities to limit city access for the dirtiest cars.

Valls said: "In France, we have long favoured the diesel engine. This was a mistake, and we will progressively undo that, intelligently and pragmatically."

Such has been the popularity of the diesel, with its lower pump price, that around 80% of French motorists drive diesel-powered cars. Valls added that taxation would have to orient citizens towards more ecological vehicles and that the 2015 state budget would seek to reduce the tax advantage of diesel fuel versus petrol.

The government has already announced it will raise the excise tax on diesel by EUR2 (US$2.50) per litre, raising EUR807m ($1bn) in 2015. Valls also said the government was working on plans to widen subsidies for converting 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 vehicle would be entitled to a bonus of up to EUR10,000 ($13,500).