VW's emissions deception feeds concerns about pollution levels of all modern cars

The industry is clear that Volkswagen was the only car manufacturer attempting to cheat emissions tests.

The stock market reaction looks sceptical. Shares in Renault, Fiat, General Motors and Ford were being sold off today. The market often gets things wrong but the sentiment seems to be "if in doubt why take the risk?"

Inquiries are springing up all over the place. In France, in Germany, in the US the Justice Agency has become involved. The British government wants the European Commission to investigate.

And this is a European problem. VW fitted 11 million of its cars with technology capable of distinguishing between a human driver and an emissions testing machine, a large chunk of those will have been sold here.

VW's deception feeds a general dissatisfaction with the quality of emissions testing. Drivers always grumble they never manage the miles per gallon on the road that companies achieve in the lab. Even the industry accepts tests need finessing.

This matters. It's not just about fuel efficiency, its about public health and global warming.

On the face of it car manufacturers have made quite astonishing technological advances in the last decade, making their fleets greener. We're faced with rather shocking prospect that the modern car is far more polluting than the official figures show.