By Jamie Lyons, PA Political Correspondent

Building new roads does not cut traffic, former Tory environment secretary John Gummer said today.

Mr Gummer is chairing David Cameron's ``quality of life'' policy group reviewing issues such as transport and the environment. He was environment secretary at the time work started on the controversial Newbury bypass 10 years ago.

"You do not reduce traffic by building new roads,'' he said today. "There is no doubt about it - there must be an assumption against road-building,'' he told the BBC Radio 4 Today programme.

Mr Gummer said sometimes the traffic and resulting local environmental damage in a particular area was so bad that a bypass was the answer. But he added: "You can only do that against a very important background, which is that you are reducing traffic overall by taking sensible measures, many of which we are not taking now.''

Mr Gummer said it would be wrong to pre-judge the findings of his group, which are not expected for 18 months. But he said his guiding principle was that it was impossible to continue polluting the atmosphere and destroying the climate.

He said that meant vehicles had to be made cleaner and more people had to be taken off the roads or on to public transport.

He said his group would look at everything afresh. But he would not be afraid if that meant admitting the party had made mistakes in the past.

"I am always happy to say that we are wrong in all circumstances,'' he said. "But what I am much happier to do is to say 'This is the way forward', having learned our lessons from the way in which we have behaved in the past, which might have been right at the time, but is not right now. The one thing you won't get me to do is to suggest we can't move forward and change simply because it means some will say 'Well, you didn't do that 30 years ago'. That would be a very peculiar kind of reform, wouldn't it?'"