Mayor Sadiq Khan has issued a high air pollution alert for the capital across Tuesday, urging Londoners to “be careful”.
The alert is a step up from Saturday’s “moderate” air pollution warning as a result of cold, still and foggy weather making it harder to dissipate car fumes.
Londoners are being urged to avoid unnecessary journeys in a bid to help lessen pollution levels.
Schools and boroughs will be notified of the alert and messages will be displayed across the TfL network.
Mr Khan said: “Following the latest forecast from Imperial College London, I am issuing a ‘high’ air pollution alert.
“We all need to be careful over the next few days. I’m urging Londoners to look after each other by choosing to walk, cycle or take public transport where possible, avoiding unnecessary car journeys, stopping engine idling and not burning garden waste, all of which contributes to high levels of pollution.
"This is particularly important in order to protect those who are more vulnerable to high pollution.”
Toxic air shortens the lives of thousands of Londoners every year.
— Mayor of London, Sadiq Khan (@MayorofLondon) January 23, 2023
We are expecting high pollution levels tomorrow. Please play your part by avoiding unnecessary car trips and not leaving your engine idling.
The Mayor claimed the high pollution alert showed it was “vital” to expand the ultra low emissions zone (Ulez) to London’s outer boroughs.
The planned move which is due to take place by August 29 has proved controversial, with eight boroughs – five Tory and two Lib-Dem councils – voicing concerns or objections.
Some have said they are prepared to legally challenge the mayor over the expansion of the scheme which charges older, more polluting vehicles.
An estimated 200,000 vehicles in the wider zone would be liable for the charge.
However, Mr Khan said last week he was “confident” the expansion would go ahead as planned.