Nearly 1.2 million UK motorists will be told to have their vehicles "corrected" because they are fitted with the software behind the Volkswagen diesel emissions scandal, the company has said.
The German car-maker announced that the vehicles affected in the UK are 508,276 Volkswagen cars, 393,450 Audis, 131,569 Skodas, 79,838 VW commercial vehicles and 76,773 Seats.
VW has not confirmed what the modification will involve for the 1,189,906 vehicles with EA 189 engines.
The firm said: "Step by step, affected customers will be contacted, with details of a process to get their vehicles corrected in the near future.
"In the meantime, all vehicles are technically safe and roadworthy."
Transport Secretary Patrick McLoughlin said: "The Government's priority is to protect the public and I understand VW are contacting all UK customers affected.
"I have made clear to the managing director this needs to happen as soon as possible.
"The Government expects VW to set out quickly the next steps it will take to correct the problem and support owners of these vehicles already purchased in the UK."
VW has admitted that 11 million of its diesel vehicles worldwide were fitted with defeat device software which conned testers into believing their vehicles met environmental standards.
The Environmental Protection Agency said 482,000 of VW's 2009-15 models in the US were fitted with the sophisticated software, which switches engines to a cleaner mode when they are undergoing official testing.
Once on the road the cars produced nitrogen oxide pollutants at up to 40 times the legal standard.
The Department for Transport has launched an investigation which will include retesting to compare laboratory results with real-world driving emissions.
Martin Winterkorn resigned as VW chief executive as a result of the scandal. He was replaced by former Porsche boss Matthias Mueller.