Cars made before 2005 may have to pay an additional charge to drive in London's most congested areas, in a crackdown proposed by Mayor Sadiq Khan to tackle air pollution.

In an announcement made on Tuesday (July 5) at Great Ormond Street Hospital, the Labour Mayor said older cars will pay a £10 emissions charge on top of congestion charges in inner London if they were manufactured before 2005.

The charge would be the most expensive of any city in the world if introduced, and an extended low emission zone affecting areas outside of central London was also proposed for 2020.

The news came as the city marked the 60 anniversary of the Clean Air Act that was passed following the great London smogs of the 1950s in a move which Mr Khan said "made a huge difference to life in London and saved countless lives".

The Mayor said: "With nearly 10,000 people dying early every year in London due to exposure to air pollution, cleaning up London’s toxic air is now an issue of life and death.

"Just as in the 1950s, air pollution in London today is literally killing Londoners.

"But unlike the smoky pollution of the past, today’s pollution is a hidden killer.

"That’s why I’m launching a hard-hitting plan of action to clean up our filthy air.

"Tough challenges call for tough measures, so I’m proposing a new £10 charge for the most polluting vehicles in central London from 2017, followed by an even stronger crackdown on vehicles pumping out hazardous pollutants."

Government must help because 'London can't do this alone'

In the public consultation, Mr Khan did not hesitate in pointing out the harsh measures were also down to former Mayor Boris Johnson and the government's failure to meet legal pollution limits, but added London needed help to tackle the issue.

"I am also calling on the government to work with me and to take more action to tackle air pollution," he told the audience.

"We can’t do this alone in London. The government should seize the spirit of the 60th anniversary of the Clean Air Act and pass new legislation fit for the 21st century.

"This needs to provide new powers and legal protections to ensure that the existing legal limits for air pollutants are retained following Brexit."

Sadiq Khan introduced the first of his environmental changes to crackdown on London's air pollution, a "silent killer", at Great Ormond Street Hospital

Dr Peter Steer, chief executive of Great Ormond Street Hospital for Children NHS Foundation Trust, said: “The Mayor’s drive to clean up the capital’s air is fantastic news for our patients and staff.

"Children living in highly polluted areas are four times more likely to have reduced lung function in adulthood, yet improving air quality has been shown to halt and reverse this effect."

At a glance: How does air pollution affect west London?

In west London, air pollution levels have been upped on the agenda for borough councils after some areas were nearly twice the legal limit, such as Brentford .

May saw Hammersmith and Fulham council push for a £1m funding boost after over 200 people in the borough died due to air quality related illnesses in a year.

Jace Tyrrell, chief executive of New West End Company representing West End businesses, commented: "We are impressed that the Mayor has set out his intentions to tackle air quality in our capital as one of his first priorities in office.

"We are fully supportive of the Mayor's consultation, and look forward to working with him and the businesses we represent to deliver a sustainable solution for improving air quality in the West End."

According to British Lung Foundation, Air pollution contributes to 9,500 early deaths in London every year.