ULEZ: What is London's Ultra Low Emission Zone?
The Ultra Low Emission Zone (ULEZ) comes into effect in central London from Monday, 8 April.
It is designed to dissuade people from driving older, more polluting vehicles into the capital.
If they do, they will have to pay a daily charge that will be in operation 24 hours a day, all year round.
It is one of a number of measures being introduced by City Hall to reduce air pollution in the city.
Transport for London has also set up a website , externalwhere you can check if your vehicle complies with the new rules.