The new toxicity levy, being dubbed the 'T-Charge', is part of a radical package of measures to crack down on the most polluting vehicles to mark the 60th anniversary of the UK's Clean Air Act this week.
The levy will apply to all vehicles, diesel and petrol, registered before 2005 and falling under the pre-Euro 4 emission standards rating.
It would be imposed by 2017 on top of the 11.50-pound congestion charge already in force on vehicles entering central London.
"Urgent action is now needed to ensure Londoners no longer have to fear the very air we breathe. That's why I'm launching a hard-hitting plan of action to clean up our filthy air.
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"Tough challenges call for tough measures, so I'm proposing a new 10-pounds charge for the most polluting vehicles in central London from 2017, followed by an even stronger crackdown on vehicles pumping out hazardous pollutants," he said.
Among some of the other measures planned by Khan to reverse this includes bringing in an "Ultra Low Emission" zone for all vehicles to meet exhaust emission standards or face a charge by 2019 and creating "clean bus corridors" in highly polluted areas of the city.
He said these proposals would be cost-neutral and would not impact a promised fares price freeze.
All these proposals are being put out for a public consultation today until July 29, after which a final decision on their imposition will be announced.