Driver and Vehicle Standards Agency (DVSA) examiners are to routinely check lorries they stop at the roadside for emissions cheat devices.
The national rollout of checks on 1 September follows a year-long pilot, during which DVSA enforcement staff caught 449 emission cheats at five sites across the country.
Cheat devices mean a lorry can produce up to 20 times more dangerous emissions.
Drivers caught with an emissions cheat device or a faulty emissions control system have 10 days to remove the device and repair the vehicle’s emissions system. If they continue to use a device or fail to repair the system, they can be fined £300 and have their vehicle taken off the road.
DVSA will carry out a follow-up investigation with the operator and may refer its findings to the Traffic Commissioners for Great Britain, who have the power to strip a company of its licence to operate.
Gareth Llewellyn, DVSA chief executive, said: “DVSA’s priority is protecting the public from unsafe drivers and vehicles.
“A vehicle doesn’t have to be falling apart to be unsafe – any driver or operator who uses cheat devices to get around emissions rules is putting the health of the entire nation at risk.
“DVSA will take the strongest possible action against anyone who tries to cheat emissions rules.”