London will implement a 24-hour a day, seven day a week Ultra Low Emission Zone, in a world first, which means vehicles will have to meet tough emissions standards or face charges.
The zone aims to reduce toxic air pollution and protect public health.
Under new rules introduced on April 8, polluting vehicles will be charged £12.50 for cars, vans and motorbikes and £100 for trucks, buses and coaches.
London Mayor, Sadiq Khan, says, "This is a landmark day for our city. Our toxic air is an invisible killer responsible for one of the biggest national health emergencies of our generation.”