A controversial scheme that charges parents who drive their children to school could be adopted by local authorities across the UK.
Richmond Council in Surrey plans to charge parents up to £75 a year for using their car on the school run.
The council says it wants to cut CO2 emissions, but the AA and a group representing parents calls it unfair.
The Local Government Association says other councils battling car congestion will watch the scheme "with interest".
From September, Lib Dem-controlled Richmond wants to charge parents up to £75 for a 15-minute parking permit allowing them to park in bays near their child's school.
Hardest hit will be the owners of vehicles such as 4x4s and people-carriers who will pay the full £75 charge. Parents with smaller cars will pay less, with the owners of the smallest, "greenest" vehicles paying nothing at all.
Previously, parents were allowed 10 free minutes parking on yellow lines - provided they used a school-issued permit.
The scheme will initially be restricted to 13 primary and infant schools in the borough, where head teachers have reported "massive amounts" of poor parking and irresponsible driving, said councillor David Trigg, who heads up traffic issues for the council.
He said: "It is a practical scheme. What we are trying to do is reduce the number of vehicles that are accessing the schools through very small streets.
"We hope it will make people think whether they do need to use their car to take their children to school, or whether they can use other methods, such as a car-share scheme."
But a spokeswoman from the National Confederation of Parent Teacher Associations said the scheme was unfair. She said it would put an extra burden on parents who had no choice but to drive their children to school.
The spokeswoman said: "If parents could walk their children to school, then they would.
"But this isn't the 1950s. These days it is not unusual for both parents to work. A lot of the time their offices are far away and they need to get their kids to school quickly."
"All this scheme will do is put an extra charge on parents."
Edmund King of the Automobile Association agreed. He said: "A lot of people think this scheme sounds like a pseudo-eco bandwagon.
"This is just another tax, and is impractical."
He defended the owners of larger cars - who under Richmond's scheme will pay the most.
"Many cars are bigger because of practicalities - they are safer, and people buy them because if you have three children then you need to have three child seats in the back."
Richmond hit the headlines in 2006 when the council decided to charge more for parking permits to residents with larger cars.
Other councils are now considering adopting that scheme. One - another LibDem-controlled council, Islington - held a referendum and found most people were in favour of charging more.
A spokesman for the Local Government Association said: "Many councils will watch this latest idea from Richmond with interest.
"All councils are now looking at ways of reducing congestion on the roads - particularly around school-run time when it causes problems for people living around schools.
"It may well be that other local authorities who have similar congestion problems will adopt this idea, if it is seen to be a success."