A mum says she may move out of London to stop the “irreversible damage” of air pollution to her children’s lungs if Ultra Low Emissions Zone (ULEZ) is scrapped.

The zone will be introduced in central London in April this year and extended to the North and South Circular roads in October 2021. Anyone driving within the zone must meet certain emissions standards or pay a daily charge of £12.50.

The Conservative mayoral candidate Shaun Bailey last week said if he is elected as the next Mayor of London in 2020 he would stop the expansion to outer London.

Jemima Hartshorn who founded and run Brixton-based environmental campaign group Mums For Lungs, hit out at Mr Bailey’s comments, branding them “irresponsible”.

Ms Hartshorn said: “The ULEZ would stop the much-needed increase of air pollution. It is critical for our children’s health.

“It is absolutely the wrong direction to go in. Air pollution levels are really unhealthy.”

Ms Hartshorn is mum to two-year-old Trissie and is expecting her second child this week.

She says if Shaun Bailey is elected as the next Mayor of London she is not sure she wants to raise her children in the capital.

Research from Kings College London found air pollution kills around 9,500 people on average each year in the capital.

Another study, commissioned by Sadiq Khan, showed there are more than 800 schools and nurseries in the capital where pupils are exposed to levels of nitrogen dioxide that breach the European Union’s legal limits.

Ms Hartshorn said: “I don’t know if we would stay in London if Sadiq Khan did not get elected. It’s really scary bringing a child into the world with these air pollution levels.”

“As a parent I lay awake at night and think ‘are we doing the right thing living in London and exposing our children to this air pollution and are we doing irreversible damage to our children for life?’”

“I don’t know if I could forgive myself if my children got sick.”

She added: “The expansion of the ULEZ must happen. We have not a moment to waste.”