The BBC's Simon Montague reports

In a BBC interview, Professor David Begg said he believed those motorists responsible for creating the most pollution should pay the most to end it.

Prof Begg said there should be less reliance on fuel tax

Prof Begg is an adviser to Deputy Prime Minister John Prescott and also chairman of the Commission for Integrated Transport, which was set up to monitor government transport policy.

He told a BBC One Panorama programme to be screened on Monday night: "Some motorists in rural areas where there's little congestion, they're not contributing much towards pollution and are paying too much.

"Other motorists, who are driving in the peak (hours) and British cities, contributing greatly towards congestion, are not paying enough."

£20 road tax?

Prof Begg said he wanted a new framework to redistribute the burden of motoring costs.

Drivers on busy roads would pay...

He said: "We need to start to place less reliance on fuel duty...and introduce charging so that where the motorway network and cities are congested and where there's more pollution, motorists pay more."

Although he did not advocate abolishing fuel duty entirely, Prof Begg said the emphasis on raising prices at the pump to discourage car use should be reduced, as should the cost of a tax disc.

He said: "You start to look at vehicle licence duty and it might be that you only get people to pay an administrative cost there - it might only be £10 or £20 to register the car."

'Blue skies' thinking

But the proposals brought a sceptical response from motoring organisations. The RAC said the idea of widespread motorway and city centre toll charging was fanciful.

...drivers on quiet roads would not pay

Spokesman Edmund King said: "The technology is not yet sufficiently established for electronic road pricing and it will not be available for quite a few years - this is blue skies thinking.

"However, it is right that the large scale increases in petrol duty are hitting people in rural areas unfairly."

They amount to an extra motoring tax without the public transport infrastructure in place to offer an alternative."

The AA agreed there was a need for a co-ordinated approach to reducing car use.