Lord Macdonald: denied he has "gone off" congestion charging

He said it was important to ensure the correct technology and better public transport systems were in place before charges were introduced.

Securing support from business was also crucial to make congestion schemes work, he said.

He did acknowledge that many local authorities were not keen to introduce congestion charging schemes.

Doubts over London

The minister also questioned whether London Mayor Ken Livingstone's proposal to have charging in place within the next couple of years was viable, and suggested that plans to implement the scheme in the capital were moving too fast.

"We have cautioned all along that this must be done very pragmatically ... our advice to the mayor has been ... do try to think it through, get it right, take all the advice that's required.

"It's important to us because if it's successful in London other councils will be more minded to take it on," he said.

Lord Macdonald also told MPs to judge the government's 10-year transport plan on its success in reducing congestion.