Nearly 1.2 million UK motorists will be told to have their vehicles "corrected" because they are fitted with the software behind the Volkswagen (VW) diesel emissions scandal, the company has today said.

The German car-maker says 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.

The RAC Foundation, which has compared the numbers released by VW with DVLA licensing data, says this means 37% of all VW diesel cars on the road in the UK are affected. It adds that this is 45% of Audi diesel cars, 25% of Skoda diesel cars and 37% of Seat diesel cars (it doesn't have the figures for commercial vehicles).

However, VW has yet to confirm what the modification will involve for the 1,189,906 vehicles with the affected EA 189 engines.

The firm says: "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."

However, some have voiced fears that these repairs may result in reduced fuel efficiency and increased CO2 emissions, which may increase the Vehicle Excise Duty motorists have to pay.

Concerns have also been raised that the scandal may devalue affected vehicles.

'Customers need to be contacted as soon as possible'

Transport Secretary Patrick McLoughlin says: "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."

The Department for Transport has also launched an investigation which will include retesting to compare laboratory results with real-world driving emissions.

Volkswagen cheats emission tests

VW admitted earlier this month 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 US 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.

Additional reporting by Helen Knapman.