I agree with the general thrust of my hon. Friend’s argument, but we should not let off the Government and all the parties in this House who supported the incentives for diesel. The health risks were known more than 25 years ago. A report by the then Environment Department in 1993, a piece in 2001 by the European Respiratory Journal and other sources all pointed out the health problems of NOx and particulates. People got the balance wrong between the perceived threat of carbon dioxide and the real threat of those poisons, but we should not pretend that there was ignorance of this issue in the past; there was not.