Volkswagen UK's managing director Paul Willis had admitted the company "has significantly let down its customers", as he faced a grilling from MPs on how the company's external investigation is going and how it intends to rectify the damage the emissions scandal has caused.
Willis added: "[Volkswagen] will take all the necessary steps to regain trust" from its customers.
Volkswagen has previously said 1.2m Audis and VW models in the UK have the "defeat device", including 400,000 Audi vehicles, 132,000 Skodas and 77,000 Seats. A further 80,000 commercial vehicles are also on the list.
Giving evidence to the Commons Transport Committee, Willis said over 400,000 1.6 litre VW cars in the UK will need both a software fix and "some injectors".
However, for close to 700,000 cars, including 2 litre models, the fix is just software related, Willis added.
Willis also confirmed that the first cars with the emissions cheat software were sold in 2008.
Also giving evidence was UK transport secretary Patrick McLoughlin, who said: "I think [VW] are going to suffer very substantial damage as a result of [the scandal], and they deserve to."
Last week VW's US chief Michael Horn admitted that he had been made aware of possible 'emissions non-compliance' a year ago and said it would take at least two years to fix the cars affected in the US and three people have been suspended.
Earlier today Standard & Poor's cut its rating on VW's long-term debt, warning further downgrades could soon follow.