Motorists are having their number plates scanned by ULEZ-style cameras 45 times every second, figures show.
Clean-driving schemes in the likes of London, Birmingham and Newcastle have all started monitoring motorists in a bid to thwart emissions and curb pollution.
But privacy campaigners are alarmed over the ever-growing surveillance networks, warning of the threat of ‘mission creep’ should the surveillance systems be abused by authorities.
Police already have access to some of the data captured by cameras patrolling low emissions areas, including London’s hated ULEZ.
ANPRs are linked directly to the DVLA database and allow local authorities to check the ownership and emissions data for cars entering their controlled zones.
If a vehicle is eligible for a charge and it hasn’t been paid, a penalty charge notice is automatically issued.
However, emissions data held by the DVLA can be incorrect, with tens of thousands of motorists having been incorrectly charged.
According to Big Brother Watch, which uncovered the figures through a Freedom of Information request, 118million number plates of cars entering Clean Air Zones (CAZ) are checked each month.
According to the RAC, there are approximately 41.7million vehicles on UK roads.
Big Brother Watch, a pressure group which monitors attempts by the state to follow its citizens, found that Birmingham City Council signed ‘a secretive’ deal with West Midlands Police to allow access to their ANPR network ahead of the Commonwealth Games in 2022.
Big Brother Watch said: ‘It gave police unfettered access to numberplate data, and this appears to still be in force.’
Birmingham City Council would not, according to the privacy campaigners, release details of the amount of data handed over as part of the deal.
In London, until early September, the Metropolitan Police had access to TfL’s CCTV traffic monitoring network until the system was attacked by cyber criminals who knocked it offline. Before the attack, between August 2023 and June 2024, the Met sought details of 163.2m vehicles.
The live CCTV network is different to the cameras enforcing the ULEZ zone. Until 2022, the Met had access to a limited number of TfL ANPR cameras covering a small section of central London.
The ULEZ cameras, scattered across London, check all numberplates against the DVLA database to determine whether a vehicle breaches emission rules.
Drivers of offending vehicles are slapped with a £12.50 daily charge.
Jake Hurfurt, of Big Brother Watch, told : ‘ANPR cameras in the UK already make up one of the biggest surveillance networks on the planet.
‘It is alarming that Clean Air Zones could grow this further.
‘Millions of innocent people’s car journeys are captured by automated cameras every day and this level of surveillance is a threat to everyone’s privacy.
‘Local authorities must be extremely careful not to undermine our privacy, even when pursuing noble aims like cutting air pollution.
‘Robust oversight is needed to make sure that even if ANPR is used in this situation, mission creep does not allow it to become part of a surveillance behemoth.’
According to TfL, which has the most extensive camera network in the UK for monitoring an emissions zone, images of cars which have either paid the ULEZ charge or are compliant or registered for a discount or exemption are deleted within 30 days of being captured.
TfL said data captured by the wider ANPR network ‘can be requested by the Metropolitan Police Service (MPS) on a case-by-case basis to support investigations’.
It stressed that no organisation such as the police or security services has ‘real time access’ to the ANPR camera network.
Figures show that TfL scans an estimated 3.3million car number plates each day to enforce the ULEZ network. A further 672,000 motorists a day are scanned by clean air zones outside the capital.
Since the extension to the ULEZ zone in August 2023 to cover the majority of the Greater London area, the number of TfL enforcement cameras has increased to more than 3,500.
TfL also has cameras which monitor traffic offences such as illegal turns, blocking yellow junctions and bus lane violations.
CCTV cameras are also fitted to London buses.
Addressing the London Assembly in June 2023, Mr Khan said: ‘The ANPR is a vital tool that assists police in identifying, locating and detaining offenders, including those suspected of serious organised crime and terrorism.’
Mr Khan said access to TfL’s camera network is on a ‘case by case basis’ and that data is stored for 12 months, ‘unless it is saved as evidence for an investigation’.
Addressing the expansion, Mr Khan noted: ‘Before the MPS gets access to any of the cameras in the expanded ULEZ there needs to be another data protection impact assessment.’
Privacy campaigners have expressed dismay over the proposals.
Sian Berry, previously a Green Party member of the London Assembly before her election to the House of Commons, questioned whether the Met Police can be trusted to access such sensitive data given the number of criminal cases involving officers misappropriating such information.
The roll-out of ANPR cameras across the UK to police clean air zones has alarmed privacy campaigners.
Birmingham City Council, which also operates a clean air zone, told they capture images of ‘non compliant vehicles’ using their ANPR system.
If they do not receive payment within 13 days, the information is passed onto ‘the statutory process that applies to penalty charge notices’.
If the correct daily fee is paid, the system deletes images of the vehicle, although the number plate is kept on the system for 180 days.
Birmingham City Council said ‘police services from across the country are able to submit a data access request to the Council as part of a criminal investigation.’
A spokesperson added: ‘No police authority has “real time” access to the Clean Air Zone ANPR cameras.’
In January 2024, revealed how TfL tried to issue 128,577 penalty charge notices to motorists which were later scrapped on appeal. In many cases, motorists could prove that the emissions data held by the DVLA and used by TfL was incorrect.
The various Low Emissions Zones have so far cost motorists in excess of £1bn in charges and penalties.
has approached the Metropolitan Police and TfL for comment.