More drivers of "gas-guzzling" cars face higher parking charges under an extension of controversial council plans.

Motorists with larger vehicles which emit more carbon, including some ordinary family cars, will now pay 25% more for on-street parking in the London Borough of Richmond Upon Thames. But owners of the greenest cars, such as the hybrid Toyota Prius, will qualify for a 25% discount.

The proposals are an extension of the current CO2 targeted parking scheme in Richmond, which varies the cost of residents' parking permits according to carbon emissions. Under the new scheme, visitors to the borough with highly polluting cars will now also be forced to pay higher meter charges. Motoring groups have reacted angrily to the proposals. Edmund King, president of the AA, called the move "counter-productive, backwards and totally unfair".

He said: "This is a tax on ownership, not on use.

"You might have a people carrier because you've got four kids, and you shouldn't be taxed for having a large family." He also expressed concern about the impact of the plan on people struggling to cope with the economic downturn. He said: "Many people can't sell their cars because the bottom's fallen out of the market. Now they are being clobbered by their local authority as well."

Stephen Glaister, director of the RAC Foundation, said tackling climate change was not a matter for local government. "This is a global problem, not a local one, and having one borough doing its own thing just causes confusion. "Richmond is only one of 33 councils in London, and motorists shouldn't have to learn a brand new system every time they enter a new borough."

Under the proposals by the Liberal Democrat-controlled council, owners of greener cars would have to register for a smart card in order to avoid paying the increased rate. If the scheme comes into force, owners of cars which emit more than 180 grams of C02 will pay up to £1.90 an hour to park at a meter.

The council predicts that 40% of its residents will be forced to pay the increased charge. Richmond Council rejected the idea that climate change is not a local issue. Councillor David Trigg, Cabinet Member for Traffic, Transport and Parking, said: "As part of our commitment to the environment, the long-term aim of this policy is to encourage people to use less-polluting cars.

"No one action will achieve this but I certainly believe local government has an important part to play and we know now that policies like this one do make most people think seriously about what they do."