More than 2 million people live in parts of London with illegal levels of toxic air

Cars will be banned from more than 12 miles of central London roads under plans to encourage the adoption of green transport in the capital.

Some of the country’s busiest roads will be turned over to bikes and pedestrians for 24 hours in the biggest dedicated event of its kind in Britain.

The move will replicate large-scale car-free days already implemented in other major capitals, including Paris and New York.

It comes amid growing concerns over the effects of air pollution on built-up areas. More than 2 million people live in parts of London with illegal levels of toxic air, including at least 400,000 children. More than half of the capital’s air pollution is caused by vehicles, particularly emissions from older petrol and diesel engines.