Volkswagen Group faced a 15 billion fine after the US environmental protection agency found it had fitted cars with software designed to cheat official pollution tests.

Their engines seemed clean in laboratory tests; on the road they emitted much higher levels of nitrogen oxide gas which can damage our health.

Although 8.5 million VW engines in Europe were fitted with the same so-called 'defeat devices', no EU state has yet to take any action against the manufacturer.

File on 4 tells the story of how the emissions scandal has spread to manufacturers beyond Volkswagen.

Europe's MEPs have voted for a new 'real driving emissions' test, but critics accuse European Council ministers of watering it down to please their domestic car industries. A proposal for an independent EU agency to oversee emissions tests and issue sanctions was blocked.

And the manufacturers have been given breathing space before they must meet the legal emissions standards - the new legislation lets them emit beyond the pollution limits for years to come.

Diesel cars were supposed to bring down emissions of the greenhouse gas CO2. But have those plans now gone up in smoke?

The programme asks whether this is the next emissions scandal and whether Europe has the power to make cars as clean as they say they are.

Reporter: Jane Deith