Minister, could you clarify about the 50 mph limits? Five of them, you're saying, are now being made permanent. What evidence have we got as to how they've worked in terms of reducing or otherwise the pollutants we're concerned about? I get representations particularly around the 50 mph limit approaching the Brynglas tunnels, and I know there can be other reasons for that, but the emphasis recently has been on the air pollution when I've had responses. I just wonder how successful or otherwise that has been. Some people suggest that the reduction to 50 mph actually causes traffic to concertina in a way that leads to some of the congestion, and an inspector on the M4 said that the relief road would reduce climate change emissions and air pollution. Clearly, you're not going ahead with that, but is this 50 mph limit having the effect you would like?

Could you also clarify—? I think you made a remark about the one in or near your constituency, about police perhaps not enforcing in the same way they would if it was a question of normal speeding. Are these limits dealt with by the police in the same way as ones where the issue is safety as opposed to air pollution?

You said in your statement that the need for rules at EU level reflects the fact that air pollution does not respect national borders. That may be the case for some pollutants—sulphur dioxide would be an obvious example—but for the ones we're most concerned about here—the nitrogen dioxide and the particulates—they're actually hyper-localised. I'm very careful when I walk my three children along a main road as part of them getting to school. Even just being on the pavement away from the cars, the medical advice is that that's significantly better.

You say you don't want us to mix up climate change and air quality, but public policy has done that. Whether it's the European Union with its diesel standards and lax or non-enforcement of those or whether it's Gordon Brown with his tax incentives to move away from petrol towards diesel, it's those in combination that have led us to much of the pollution problem we have now for air quality on the nitrogen dioxide and on the particulates, which are so severe and which, as Andrew R.T. Davies said, are killing 2,000 people a year prematurely. Do you now accept that it was a mistake to incentivise a switch from petrol to diesel? And while, no doubt, you would prefer people to go electric and the UK Government's just withdrawn some of the incentives on that, is it better for people to buy petrol rather than diesel cars, notwithstanding the higher carbon dioxide emissions in that area? Thank you.