A serious debate is needed on road pricing if Britain is to effectively tackle congestion, Ruth Kelly has said.

Speaking during a debate on sustainable communities at the Labour Party conference in Bournemouth on Thursday, the transport secretary told delegates that it was impossible to "build our way out of road congestion".

"So let us have the debate on road pricing, and as we do I look to our towns and cities to take the lead in showing how better public transport and measures to reduce congestion go hand in hand," she said.

Kelly claimed that the twin threats of international terrorism and climate change were the big challenges facing the country.

Speaking of the attempted terror attacks in London and Glasgow, she stressed the importance of keeping transport "open and secure".

Although the minister acknowledged that the government had "not got everything right" on transport, she insisted that "real progress" had been made.

But "rising aspirations, congestion and climate change mean we have to do more," Kelly added.