London ULEZ expansion: Sadiq Khan opposed by Home Counties
Sadiq Khan is facing strong opposition from authorities bordering London over his plans to expand the ULEZ project.
Authorities including Essex and Buckinghamshire are refusing to allow warning signs and cameras to be placed on their land.
Hertfordshire County Council is also against the London mayor's plans to expand ULEZ.
The mayor's office said it was "working closely" with the councils to install the necessary infrastructure.
Mr Khan wants to expand ULEZ - which means certain vehicles must pay £12.50 a day to drive - to cover all of the capital's boroughs from August, in a bid to improve air quality.
Last week Surrey and Kent county councils announced they would be blocking any ULEZ signage on their land.
Within London, the boroughs of Bexley, Bromley, Harrow and Hillingdon have all vowed to continue fighting plans to expand the zone.
In an open letter to the mayor, they said their boroughs "enjoy good air quality" with levels of harmful gases "considerably below the levels in inner and central London".
It added: "With such little benefit to be gained from the expansion of ULEZ, very careful consideration must be given to the adverse impacts it will have on residents and businesses, and we believe that you have failed to give sufficient weight to this."
Despite their objections, Mr Khan and Transport for London (TfL) still have the power to install ULEZ signs and cameras on the boroughs' roads using "direct installation powers".
But these do not extend beyond the capital - meaning his plans to extend the zone to his desired blueprint could be hampered.
It could force Mr Khan to create a buffer zone within the ULEZ area to give drivers sufficient warning.
Lee Scott, responsible for highways and transport at Essex County Council, said the authority "will not allow any other areas to use the county council's land for cameras or other equipment related to the proposed expansion of the Ultra Low Emission Zone".
Steven Broadbent, responsible for transport at Buckinghamshire Council, said the authority was "refusing to agree permission for Transport for London to erect signage within Buckinghamshire promoting the expansion of the ULEZ".
He said it supported "intentions to improve air quality and reduce carbon emissions" but did not believe the ULEZ expansion was the "right way".
Councillor Richard Roberts, leader at Hertfordshire County Council, said that while he welcomed the principal aims of ULEZ, "the full impact on the towns and villages bordering London has not been assessed and so we are unable to give our full support at this stage".
A spokesperson for Mr Khan said: "The mayor has been clear that with 4,000 Londoners a year dying prematurely from toxic air [a claim made in a study commissioned by City Hall] his decision to expand the ULEZ should be implemented without delay.
"In doing so we are working closely and collaboratively with the local authorities concerned to install the infrastructure needed."
Follow BBC London on Facebook, Twitter and Instagram. Send your story ideas to [email protected]