Sadiq Khan won election last week by a record margin and has promised a raft of measures to make London one of the greenest cities in the world, including more low-emission buses and charging points for electric cars.
Carmakers are facing increasing pressure to bring down emissions in the wake of the Volkswagen diesel scandal as they face tougher European regulations from next year.
Under proposals released on Friday, drivers of the most polluting vehicles may have to pay an extra charge for entering central London from 2017 and an ultra-low emission zone (ULEZ) could be introduced sooner than currently planned.
The ULEZ, in which cars must meet stringent emissions standards to enter or pay a charge, is due to come into force from September 2020 in the City of London and the West End but could be extended to cover other major roads.
Khan said he wanted to take pre-emptive action to tackle high levels of pollution especially in areas around schools.
“I know from personal experience that the city’s air is damaging people’s health,” he said.
“I want to act before an emergency, which is why we need big, bold and sometimes difficult policies if London is to match the scale of the challenge.”
A public consultation is due to begin in the next few weeks.