Carmakers that cheat on emissions tests could be given unlimited fines under a strict new regime

Importers would also be hit under the plans being considered by the Government

Firms installing devices that mask the true level of noxious gasses coming from cars during lab testing would also face criminal charges

Carmakers that cheat on dirty emissions tests and try to sell the vehicles in Britain, could be punished with an unlimited fine under a strict new regime.

Firms that install “defeat devices”, which mask the true level of noxious gasses coming from cars during lab testing, would also face criminal charges under the government proposals.

The new system could see importers as well as manufacturers hit for dealing with cars that have the devices.

It follows the Volkswagen emissions scandal, which saw the firm caught for fitting the defeat devices to cars, including more than 1.2 million that ended up in the UK.

Transport minister Jesse Norman said: “We continue to take the unacceptable actions of Volkswagen extremely seriously, and we are framing new measures to crack down on emissions cheats in future.

“Those who cheat should be held to proper account in this country, legally and financially, for their actions.”

On Thursday, ministers launched a consultation into the plans, which would see companies responsible facing criminal charges and a substantial fine for selling new vehicles containing software designed to deceive emissions tests in the UK.

The new powers would go above and beyond European requirements, enabling the Government to prosecute any importer who brings a non-compliant product to the UK.

In 2015, the US Government discovered Volkswagen had programmed turbocharged direct injection diesel engines to activate their emissions controls only during lab testing.

It caused the vehicles’ noxious emissions output to meet US limits but emit some 40 times more when driving elsewhere, and it later emerged that the company had used the programming software in about 11 million cars worldwide.

In Britain, the Department for Transport then set up a programme to test a range of the most popular diesel vehicles, which found that no other manufacturer tested was using a similar strategy to Volkswagen.

The German firm reimbursed the British taxpayer £1.1m for the costs of the programme, but has found itself in the news again this week amid a furore over tests it carried out in which monkeys were locked in containers and exposed to toxic diesel fumes. Humans also breathed the fumes as another part of the test.

The DfT also announced on Thursday plans to ensure consumer information on the fuel economy of new cars, includes results from a new more rigorous laboratory test cycle.

It also brought in measures to improve the environmental performance and safety of specialist and modified vehicles, while stricter rules on the sale of vehicles that do not adhere to the latest emissions rules were also implemented.

It comes alongside the Government’s commitment to end the sale of conventional new diesel and petrol cars and vans by 2040.