TWO north London boroughs are set to link the cost of residents' parking permits to car CO2 emissions.

In a UK first, drivers of gas guzzling four-wheel-drives would have to pay far more to park outside their homes.

The changes were given the go-ahead by Camden and Haringey councils last night.

Richmond, Tower Hamlets and Lambeth councils, all in London, have said they plan to introduce similar schemes.

In Camden, drivers of electric cars will be given parking permits free of charge and will also be given free short-stay parking in pay and display bays.

The council also announced a trial of a number on-street re-charging points for electric cars.

The charging bays will be installed south of Euston Road by March 2008 and will be available for drivers to share and use for a limited time.

Cllr Mike Greene said that under the new permit plan, which could be introduced by the end of May, the majority of Camden residents would actually be paying less.

"We want to encourage residents to take alternative transport to help tackle CO2 emissions, but when people do need to drive this offers them an incentive to switch to lower emission and electric cars if possible," he said.

The council estimates that about four out of 10 residents could pay more for their permit.

Drivers of the lowest tariff cars would pay 22 per cent less than the current cost of £90 for an annual permit. Owners of the highest emitting vehicles would pay 61 per cent more.

In Haringey, the sliding scale will halve the cost of permits for owners of energy efficient cars, while owners of high-polluting vehicles will pay almost four times as they do currently.

A permit for a Smart car will be just £15, while the owner of a Ford Mondeo or Range Rover will pay £90.

The cost of a second permit will also rise substantially in a bid to deter residents from buying multiple cars.

Cllr Brian Haley said the number of cars in Haringey increases every year.

"We know some people will be delighted with this policy, while others will respond with anger or skepticism," he said.

"But we firmly believe it is right that we should actively tackle global warming at a local level, and if this new charging policy makes residents think twice before purchasing a 4x4 or a second vehicle for their household, then it will have served its purpose."

Haringey will now begin a 21-day consultation with residents, with a view to implement the scheme in April.