Sadiq Khan has pleaded with three councils to allow ULEZ warning signs to be put up.
A spokesman for the London Mayor urged the Tory-run authorities in Surrey, Kent and Hertfordshire to “do what’s best for their residents and drivers”.
The zone will be widened to cover the whole of London in less than two weeks meaning more drivers will be forced to pay the £12.50 daily charge for the most polluting vehicles in a bid to improve air quality.
His spokesman said: “Councils have a responsibility to ensure their residents and all motorists are aware of important changes that may impact drivers.
“By refusing to allow TfL to install Ulez warning signs at key junctions, these councils outside London are not fulfilling their responsibility to ensure their residents and other motorists have all the information they need to avoid driving into the Ulez inadvertently.
“The mayor is urging these three county councils to put their politics aside and do what’s best for their residents and drivers.”
