The British government has announced it is to set up its own investigation into vehicle emissions in the wake of the Volkswagen (VW) scandal in the US.
Transport secretary Patrick McLoughlin said the government is taking the "unacceptable actions" which resulted in the the resignation of Volkswagen chief executive Martin Winterkorn stepping down very seriously.
The car company was found to have manipulated emissions data to make it appear like some of its vehicles were more environmentally friendly than they actually were.
The UK regulator of emissions, the Vehicle Certification Agency, said it will work with carmakers and make them rerun tests if necessary as part of the inquiry. German transport minister Alexander Dobrindt revealed that as well as the estimated 11 million cars driving with falsified software in the US, cars in Europe could also be affected too.
McLoughlin said: "The government takes the unacceptable actions of VW extremely seriously. My priority is to protect the public as we go through the process of investigating what went wrong and what we can do to stop it happening again in the future.
"We have called on the EU to conduct a Europe-wide investigation into whether there is evidence that cars here have been fitted with defeat devices.
"The Vehicle Certification Agency, the UK regulator, is working with vehicle manufacturers to ensure that this issue is not industry-wide. As part of this work they will rerun laboratory tests where necessary and compare them against real world driving emissions."
Separately, The European Commission added: "We invite all member states – in addition to the ones who are already doing so – to carry out all the necessary investigations. We need to have the full picture of whether and how many vehicles certified in the EU were fitted with defeat devices, which is banned by EU law."
All new vehicles must pass emissions tests before going on sale to the public. This involves parking the car on a dynamometer – also known as a rolling road – and running its engine in a series of ways.
The contents of exhaust emissions – mostly carbon dioxide and nitrogen oxide (NOx) – are monitored and checked against the legal maximum, which varies by country. In the US, where the emissions fraud was uncovered, the limit is 31mg of nitrogen oxide per km driven. In Europe this is 80mg, making it much easier for car makers to comply.