In a statement, an HMRC spokesperson said: "Company car tax is based on the CO2 emission figures for the particular type of car, shown on either the UK approval certificate or the EU approval certificate. As the car benefit charge is calculated on the basis of the figures shown on the approval certificates, the tax position for Benefit-in-Kind purposes remains unchanged."

The confirmation follows the Department for Transport announcement that owners of affected vehicles won't be penalised with Vehicle Excise Duty rises as it readies for laboratory and real-world emissions tests on Volkswagen Group models already confirmed to contain the software.

Transport Secretary Patrick McLoughlin said: “Our priority is to protect the public and give them full confidence in diesel tests. The Government expects Volkswagen to support owners of these vehicles already purchased in the UK and we are playing our part by ensuring no one will end up with higher tax costs as a result of this scandal.

“I have been pressing for action at an EU-level to improve emissions tests and will continue to do so. I have also called for a Europe-wide investigation into the use of ‘defeat devices’, in parallel to the work we are doing in the UK.”

Volkswagen has already confirmed that nearly 1.2 million UK vehicles feature the software and will be recalled. Car dealers will be notified in the coming days of the VIN (Vehicle Identification Number) details of affected cars while a self-serve process for customers to check if their vehicle is affected will also be set up.

The carmaker has also removed around 4,000 cars from sale in the UK as they were fitted the EA189 Euro 5 engine at the centre of investigations into its manipulation of US emissions tests. The vehicles affected by the move are from Audi, SEAT, Skoda, Volkswagen, and represent around 3% of the group’s total UK stock.