Germany’s diesel ban could see its deadly air pollution problem exported to Romania, Bulgaria and other eastern European countries, experts fear.

A court last week gave German cities the green light to stop the most-polluting diesel vehicles from using its roads.

Hamburg said it would begin implementing limits at the end of April, while Stuttgart and Duesseldorf have also been told they should consider bans. Other German cities are expected to follow suit.

Experts say the backlash against diesel and city centre restrictions on the most-polluting vehicles will see German car owners look to sell.

Julia Poliscanova, an air quality expert at Transport & Environment, told Euronews Germany's discarded diesel cars are likely to find their way to Romania, Bulgaria, Poland and the Czech Republic.

“If you have a relatively new diesel car [in Germany] and it’s worth nothing anymore and you know that in a few weeks you can’t take it into the city centre to go shopping, what will you do? You’ll try and get rid of it,” said Poliscanova. “That is something that can be seen across millions and millions of polluting vehicles.”

Germany’s ban is the latest part of a global backlash against diesel cars, which has accelerated since carmaker Volkswagen admitted in 2015 to cheating US exhaust tests.

Paris, Madrid and Athens say they plan to ban diesel vehicles from their city centres by 2025, Rome a year earlier. Copenhagen’s mayor wants to begin restrictions as earlier as next year. France and the UK will ban new petrol and diesel cars by 2040.

But while momentum is building on tackling air pollution in major cities in western Europe, it’s not on the agenda in central and eastern parts of the EU, according to Poliscanova.

“In eastern and central Europe there are no low emission zones or diesel bans and there might be a situation where all these diesel cars — that are now worth much less and western Europeans don’t want to use anymore — will all be shipped secondhand to central and eastern Europe and cities like Sofia and Prague will have pollution for years to come.

“We believe it should be evaluated what measures can actually be put in place so that other cities in eastern Europe do not allow or register these secondhand cars unless they have been fixed or upgraded.”

Poland, which was officially told last month it had breached EU air quality standards, has some of the most polluted cities in the bloc.

They include Krakow, which has the country’s highest ranking for particulate matter (PM10) caused by diesel engines, among other sources.

Agnieszka Warso-Buchanan, a lawyer with Client Earth, said she hoped Germany’s diesel ban would spark the development of clean transport zones in Poland.

She said: "However, we are afraid that the negative consequences will soon affect us: the increased importing of diesel vehicles withdrawn from the German market and thus the increase in air pollution in the centres of Polish cities.”

Environmentalists in Romania also say they are worried about the knock-on effects of Germany’s ban.

“This is definitely credible,” Carla Donciu, public relations manager at Greenpeace Romania told Euronews.

“Four out of five cars registered in Romania last year were secondhand cars, cars that pollute, cars that add to the already infernal traffic of Bucharest, the fifth most crowded city in the world.

“We have no pollution tax for cars, which makes Romania a heaven for old and polluting cars.

“Authorities do not encourage or support healthy alternatives and the government does not actually fight air pollution. The country faces an infringement procedure from the European Commission for exceeding agreed air pollution limits.”