The picture shows traffic conjestion in central London, Britain, Aug. 28, 2003. (Xinhua photo/Wang Dingchang)

LONDON, Oct. 23 (Xinhua) -- The world's toughest pollution tax came into operation Monday when thousands of drivers faced paying a vehicle emission charge to enter central London.

The 10-pounds (13.2 U.S. dollars) so-called T-charge applies to older and more polluting vehicles and will be additional to the current London congestion charge.

It will take the fee for pre-2006 vehicles entering London to 21.50 pounds (28.4 U.S. dollars), costing some drivers who commute into London by vehicle more than 100 pounds a week (142 U.S. dollars).

The office of London mayor Sadiq Khan said the charge is expected to affect 34,000 vehicles every month, with critics complaining it will affect the poorest Londoners.

Mayor Khan said Monday the charge is a response to London's poor air quality, saying that around 9,000 people in London die prematurely every year from illnesses linked to polluted air.

City Hall in London said the Toxicity Charge, which came into force from 7 a.m. local time, affects pre-Euro 4 vehicles, affecting mainly diesel and petrol vehicles registered before 2006. These are vehicles that do not meet standards for both PM and NOx emissions.

Khan said such polluting vehicles have made around 2.6 million trips within the London charging zone since January 2017.

The charge is also aimed at preparing Londoners for the early introduction of an Ultra-Low Emission Zone, which Khan is proposing to introduce as early as April 2019 and which will affect thousands more vehicles in the existing congestion zone, including diesel vehicles.

Khan said: "Today marks a major milestone in this journey with the introduction of the T-Charge to encourage motorists to ditch polluting, harmful vehicles. London now has the world's toughest emission standard.

"Filthy air is causing a public health crisis in the capital. Recent health data has shown 7.9 million Londoners -- nearly 95 percent of the population -- live in areas exceeding the World Health Organization guidelines on toxic air quality particles," he said.

Professor Stephen Holgate from the Royal College of Physicians said: "The implementation of the T-charge is a positive step towards cleaning up London's air and it is showing to the world that it is possible to change behaviors in order to reduce the harms from high polluting vehicles. Such actions will improve the air quality in our capital and in time will save lives."

Campaign group, Clean Air London, said the mayor's measures did not go far enough, with a call for even tougher measures.

Spokesman Simon Birkett said: "The Mayor pledged to restore London's air quality to legal and safe limits and that means he has to do a whole lot more. We want him to take steps which are bigger, stronger and smarter."