Sadiq Khan launched his plans to clean up London’s air at a primary school in the south of the borough, which will be the first to be undergo an air quality audit.

Prior Weston in Whitecross Street is near to Beech Street, which has pollution levels that are twice the legal limit.

It will be the first of 50 schools audited in a bid to protect kids from toxic air, along with St John Evangelist RC Primary School in Duncan Street. Mr Khan met pupils at Prior Weston on Wednesday at the project’s unveiling.

He said: “It is shameful that children across London are breathing in toxic air simply by going to and from school. I am determined to do everything in my power to safeguard their health.”

Ways to improve air quality include cycling, walking, reducing emissions, moving school entrances and play areas away from busy roads.

Local London Assembly Member, Jennette Arnold AM, said: “We now need the government to follow his lead and take steps to tackle London’s toxic air.” The audits will be completed by the end of 2017.