Improving air quality is a priority for the Government and in particular for the Secretary of State for Environment, Food and Rural Affairs. Our plans have always followed the best available evidence, but we are ready to update those if necessary. We have been at the forefront of action in Europe to make sure that there is more accurate real world emissions testing of diesel cars in particular. I can point the hon. Gentleman to the green transport initiative and to plans to introduce clean air zones around the country. There is no instant solution to this problem, but it continues to be a Government priority.