Sadiq Khan has announced that he will close 20 kilometres of roads in the capital city as part of a car-free day.
The plans are set to take place on Clean Air Day - Sunday 22 September - with events happening across eighteen of the London boroughs.
The Mayor of London said the move was aimed at encouraging Londoners to “reimagine” their city without cars.
“London is leading the way in innovative measures to improve air pollution and I want this year’s car-free day events to be the best of any world city,” said Mr Khan said.
“This will be a great opportunity for us all to leave our cars behind and explore our streets by foot, or by bike.”
He added: “Hopefully this will shame into life those boroughs with outdated views who are dragging their feet.”
The car-free day is part of Mr Khan's bigger ambitions to have 80 per cent of all London journeys being taken via sustainable modes of transport by 2041.
This comes after a Transport for London survey found almost one in two Londoners did not realise vehicles were the main cause of air pollution.
The Ultra Low Emission Zone was introduced in April
Earlier this year, a new Ultra Low Emission Zone (ULEZ) was implemented in London.
The zone’s aim was to reduce the number of polluting cars in the capital, with an estimated 40,000 vehicles being affected each day.
Older and more polluting vehicles now have to pay £12.50 to enter the area, in addition to the congestion charge.
The founder of Mums for Lungs, a group of parents concerned about pollution, welcomed the car-free day.
Jemima Hartshorn said: “Road traffic is the main contributor to air pollution in London and the car-free day is therefore a first step to showing us all how healthy, fun and accessible many parts of London are without road transport.”