Congestion charging in London has been hailed a success

The pay-as-you-drive rush hour charges would "take an awful long time" to be accepted, the AA said.

The Association of British Drivers (ABD) was also sceptical, saying the scheme was a way to make up for diminishing petrol tax revenues.

HAVE YOUR SAY I see protests along the lines of the fuel duty protests if this idiot idea goes any further Dave, UK Send us your comments

But Transport Secretary Alistair Darling defended the plans, dismissing opponents as "extremely foolish".

Under the plans, satellite tracking devices would be fixed to cars. Journeys would then be monitored and charged accordingly.

Mr Darling said a nationwide system could be at least 10 years away but said: "If we don't start thinking about it now, we are going to face a situation where we will have very, very severe traffic problems."

The charging meter on your dashboard flashes up the price of the trip... when you arrive at your destination, with a bleep your credit card is charged The BBC's Tom Symonds How the charging scheme could work

ABD spokesman Tony Vickers said petrol use would reduce in the next 10 to 20 years as cars moved to pollution-free hydrogen fuel.

"The government is looking for ways to continue the disproportionate amount of tax they're draining from motorists by finding new ways of taxing them," he told BBC Radio 4's Today programme.

But Mr Darling told Today the scheme was a better idea than simply letting traffic build up.

"If you turn your mind against it from the start then you are extremely foolish.

"Congestion is the worst thing we can do to the motorist. If we don't do anything we will be faced with a situation where frankly more and more of our roads are simply gummed up."

Alternative plans

Last year, the government predicted traffic jams could increase by up to a fifth by the end of the decade.

If you take this morning, at 8.50am, one in five cars on the road will be on the school run Alistair Darling Transport Secretary

In 2006, road charging will be introduced for lorries by using satellite tracking.

Mr Darling also said he was discussing with Education Secretary Charles Clarke other ways of tackling school-run congestion.

These could include US-style yellow school buses or staggered school opening hours.

"If you take this morning, at 8.50am, one in five cars on the road will be on the school run," he said.

An RAC survey found that 76% of drivers would accept congestion charges if they were "revenue neutral" - that is, if there were associated cuts in petrol and road tax.

On Tuesday Mr Darling will meet academics and motoring organisations to discuss the issue.

He will at a later date be able to examine a nationwide picture of congestion from a study expected to finish next year.

Mr Darling said the government would not want to make money out of the scheme.