You can bet this thorny issue is going to be bumped down the road to the next government.
http://www.bbc.co.uk/news/science-environment-30119279
The UK government will come under renewed pressure to cut pollution from diesel vehicles following the latest ruling in a battle over clean air.
Nitrogen dioxide in cities is illegally high and the European Court of Justice ruled judges must force ministers to clean up the air as soon as possible.
The pollutant comes almost entirely from diesel vehicles.They say that could force ministers to order a major retrofit of pollution controls on buses and lorries; ban diesel cars from cities; and install new technology to ensure that diesel cars comply with the emissions data from manufacturers.