Drivers trying to check whether they have to pay ultra-low emission zone (Ulez) charges are waiting several minutes as Transport for London’s website struggles to cope with demand.

Motorists are greeted by a message that states: “Our website is busier than usual. You are now in a queue, and your expected wait time is 3 minute(s). If you prefer not to wait, please try again later.”

The Ulez expansion, which means the worst-polluting cars throughout Greater London will incur a £12.50 daily charge, took effect today.

An AA spokesman said: “Some AA members experienced delays checking with the TfL website whether their vehicles were compliant this morning. Most members did get through after waiting several minutes.”

Sadiq Khan, the London Mayor, has offered people cash to upgrade their old cars so they can avoid having to pay the charge. However, critics have warned that the £2,000 payments do not go far enough.