Battery electric cars are poised to overtake diesels on Great Britain’s roads by 2030, according to analysis that suggests London will be the first UK city to go diesel-free.

The number of diesel cars on Great Britain’s roads in June had fallen to 9.9m in June last year, 21% below its peak of 12.4m vehicles, according to analysis by New AutoMotive, a thinktank focused on the transition to electric cars. Electric car sales are still growing rapidly, albeit more slowly than manufacturers had expected.

However, the transition to cleaner vans is lagging behind cars, and the number of diesel vans has continued to rise, to a record 4.4m.

The UK went through a “dash for diesel” cars in the 2000s as the government granted them cheaper tax rates. Diesel engines tend to be more efficient than petrol engines, burning less fuel and producing less carbon dioxide.

However, they also produce more nitrous oxides, which are harmful to health. In 2015 Volkswagen was found to have created software to cheat on emissions tests, kicking off the “Dieselgate” scandal, costing it alone €30bn (£26bn) around the world in fines, compensation and legal costs. Analysis this year suggested the extra emissions from cheat devices from Volkswagen and other carmakers were responsible for thousands of deaths and cases of asthma.

Sales of cars with diesel engines duly plummeted, to fewer than 100,000 in the first 11 months of 2025. However, it will take some time for the share of diesel cars on the road to diminish, as many cars bought during the peak years of diesels are only now being scrapped.

Battery electric cars made up only 4% of the cars on UK roads last year, compared with 32% diesels and 58% that use petrol, according to the Society of Motor Manufacturers and Traders (SMMT), a lobby group. The other 6% were hybrids, which mostly combine a smaller battery with a petrol engine.

Nevertheless, the number of diesels should drop as older cars are scrapped, delivering benefits for towns and cities where particulates tend to be concentrated. That will also have a knock-on effect for filling stations, leading to many withdrawing diesel supplies.

London is expected to be the first place in the UK where no diesel cars or vans are registered, largely because of the ultra-low emission zone (Ulez), which applies charges for more polluting non-compliant cars. Diesel numbers are also dropping rapidly in the central belt of Scotland, which contains Edinburgh and Glasgow, both of which have low-emission zones.

“Ending the use of diesel is essential to clean up Britain’s choking cities,” said Ben Nelmes, the chief executive of New AutoMotive. “The UK is now rolling out electric cars at a rapid pace, and this is great news for everyone that enjoys clean air, quieter streets and really cheap running costs.

“The UK imports billions of pounds of diesel every year, and we have been completely reliant on other countries to feed our thirst. Thankfully, we’re switching to electric cars at a rapid rate, and that will make the country cleaner and wealthier.”

However, the analysis found that people in cities appeared to be selling their diesels to people in more rural areas.

The report found that, while the number of diesel vans has risen over the past decade, the peak of new diesel van sales probably happened before the pandemic, meaning the numbers on roads will eventually fall.

Matt Finch, an environmental policy expert who co-wrote the report, said the world was “leaving the diesel age”. He said: “No one is denying diesel hasn’t been useful, but it has had its day.”