In their most dynamic move for years, the UK’s biggest sellers of diesel engines came together today - via their uniting body, the Society of Motor Manufacturers and Traders (SMMT) - in a bid to stop the recent demonisation of diesel engines.

They tried to explain that, far from being part of the problem, latest Euro 6 designs are part of the solution both to improving air quality and reducing CO2.

At a morning meeting in central London attended by the UK chiefs of Ford, BMW, VW Group, Vauxhall and Jaguar Land Rover, SMMT CEO Mike Hawes presented research showing that three-quarters of UK motorists were against penalties for the country’s cleanest diesels. He also said that a staggering 87% of them had never heard of Euro 6, the clean-air standard due to be implemented later this year (and embraced long ago by many of the majors).

Euro 6 has already all but eliminated particulates from diesel exhausts and put them close to petrol engines as low producers of smog-inducing oxides of nitrogen - while maintaining the diesel’s long-time attraction of producing around 20% less CO2 than equivalent petrol units.

Car manufacturers have become alarmed by what they see as inappropriate parking penalties about to be imposed on diesel cars by London boroughs, by suggestions that Paris may be the first of several European capitals to ban diesels from its centre, and by highly publicised academic research that has failed to acknowledge latest technological advances.

Car makers deserved credit for achieving a fleet target of 130g/km two years early, said Hawes, but legislators needed to acknowledge the role diesels would have in reaching the next, much tougher target, 95g/km by 2020.

Average CO2 output was down 29% since 2000, while NOx output from diesel cars had fallen by 84% in the same period. In any case, cars of all kinds accounted for only 14% of the UK’s NOx emissions - which meant it would take the annual output of a staggering 42 million Euro 6 diesel cars to dump as much NOx in the UK’s atmosphere as just one large coal-fired power station.

It was a bravura performance by a bunch of committed and high-powered people with very good facts to back them up. All agreed this wasn’t the end of the effort - especially since some of the impact in the news media was reduced by competing tales of Jeremy Clarkson allegedly lamping his producer - but it was a very good start. One had the feeling that this was an attractive argument than would only become more effective with time.