An area of central London where motorists must pay an unpopular congestion charge on week days will be expanded starting February next year, London Mayor Ken Livingston announced Friday.

Motorists will have to pay eight pounds (12 euros, 14 dollars) per day for the privilege of driving in the neighborhoods of Knightsbridge, Kensington and Chelsea from Monday through Friday.

Drivers have since 2003 paid a charge to travel in the City of London, the city’s financial district, and the West End, the city’s main commercial and entertainment center.

Motorists and merchants alike expressed their anger when the fee went up in July to eight pounds from five pounds. An estimated 136,000 people live in the current zone.

Livingston, who was re-elected last year, has said the charge had helped reduce road congestion in the two years it has been in place and increased revenue used to support public transportation.

The charge — the world’s most ambitious attempt at urban road pricing — has been credited with reducing congestion in central London by 30 percent with 70,000 fewer vehicles entering the charge zone.

Businesses say the increase will deter shoppers from driving into the heart of London, the biggest capital city in the European Union.

However, Greenpeace, the environmental organization, welcomed the extension.