Sadiq Khan has urged councils just outside of London to allow new Ultra Low Emission Zone (Ulez) notice signs to be put up.
The Mayor of London has asked three Conservative authorities in Surrey, Kent and Hertfordshire to allow the installation of warning signs of Ulez boundaries.
A spokesperson for Khan urged the home counties to “do what’s best for their residents and drivers”, after the authorities have refused to allow signage to be introduced.
From August 29, Ulez will cover the entirety of Greater London, forcing motorists on the capital’s outer boundary to cough up cash to cover the £12.50 daily levy.
Transport for London (TFL) has offered to pay the full cost of installing and maintaining the signs, City Hall has said
Khan is worried that without the warning signs put up, some drivers could enter the zones by mistake.
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 (Transport for London) 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.”
TFL has offered to pay the full cost of installing and maintaining the signs, City Hall has said.
National Highways has cooperated with the transport authority, meaning the signs are in place on major roads leading into the zone.
Surrey, Kent and Hertfordshire councils have confirmed they would not install any signs.
Matt Furniss, a cabinet member for transport at Surrey Country Council said that they will not set up signage “whilst there isn’t any mitigation in place to minimise the impact of the expansion on Surrey residents”.
A Kent County Council spokesman said: “We fully understand and appreciate our obligations as a highways authority, and the safety of road users is always our priority.
“We stand by our decision not to adopt Ulez signage for as long as there is no mitigation to minimise the impact of the expansion of the scheme on Kent residents.”
Hertfordshire County Council said the Ulez expansion to Hertfordshire's borders would "price some of the lowest paid in our county off the roads".
"No amount of signage will change the fact that our residents and businesses face a £12.50 penalty for travelling into the capital," they added.
Khan has urged the home counties “do what’s best for their residents and drivers”
Khan announced earlier this year that a scrappage scheme for non-compliant cars worth up to £2,000 would be extended to include all Londoners from August 21.
It currently only applies to those receiving benefits.
Furniss said that the extended scrappage scheme would “have no impact on those outside of London”.
He urged Khan to “do what’s right” and extend the scheme outside of London.
A TfL spokesperson said they have detected three locations where they believe the lack of signs will “increase the risk of unsafe manoeuvres”.
The locations are on the Stanwell Moor Road approach to the roundabout with the Southern Perimeter Road of Heathrow Airport in Surrey, Hewitts roundabout in Kent and the A411 approach to Stirling Corner roundabout in Hertfordshire.
TfL believes signage will be “of benefit” to residents in the three home counties and have begged to councils to work with them.