Watch: VW boss accused of not telling whole truth to MPs over emissions scandal

In a strongly-worded letter to Mr Willis, the managing director of VW in the UK, the senior Labour MP questioned the firm's compliance with Government requests for money and information, and asked for further details about the fixes applied to vehicles.

The MPs also demanded clarification about whether all findings from an investigation by law firm Jones Day had been published.

During his evidence to the transport select committee, last week Mr Willis said that while paying £12.3 billion to settle claims in the US and buy back polluting cars, there was "no legal basis" for similar claims in Britain, he had "misled nobody" and that his company did not set up cars to cheat emissions regulations.

Mrs Ellman told him the committee considered that his evidence to them in a hearing in February and a subsequent letter in March "fell short of our expectations in a number of ways".

She listed eight points on which the MPs wanted answers from Mr Willis.

Mrs Ellman said: "Volkswagen's actions on emissions raise important questions that deserve answers. I have written to Mr Willis to give him the opportunity to clarify and expand on his evidence before the committee."

Paul Willis, Volkswagen Group UK managing director defends a failure to provide compensation at the parliamentary committee. Source: parliamentlive.tv

Mr Willis told MPs that fewer than half of the UK vehicles caught up in the Volkswagen emissions scandal had been fixed. Around 470,000 of the 1.2m vehicles fitted with software to cheat environmental tests have been dealt with, he said.

SNP MP Stewart McDonald, who is a member of the committee has previously written to the Volkswagen managing director raising concerns about the compensation failure and the clearness and inconsistencies of his evidence saying the evidence session was "extremely disappointing and unacceptable".

During the hearing, MPs attacked VW’s UK boss for failing to give answers to straight answers, repeatedly using phrases such as “to the best of my knowledge” and “I can’t recall”.

In the UK around 1.2 million diesel engine cars are affected by the emissions scandal.

Of the UK vehicles affected by the crisis, there were estimated to be 508,276 Volkswagen cars, 393,450 Audis, 131,569 Skodas, 79,838 VW commercial vehicles and 76,773 Seats.

Around 20,000 cars a week are being fixed by the company, Willis told MPs.

Mr Willis was being questioned by the transport select committee on the emissions scandal following revelations in 2015 that 11m diesel-engined VW cars worldwide failed to meet pollution controls.

Willis said there had been no change in fuel consumption and, from all the data he had seen, there had been no detrimental effect to the residual value of vehicles.

VW accepts that 8.5 million vehicles in Europe were fitted with software that could detect when they were being tested for emissions.

But it denies that the software amounts to a "defeat device" under EU law.

During the hearing it was claimed that payments to cover the cost to the taxpayer of re-testing vehicles had not yet been fully paid with ministers seeking a further £1 million over and above the £1.1 million paid by Volkswagen.

Transport minister John Hayes told MPs that the government were engaging with VW to cough up the further cash and to press for further compensation to customers who have been affected.

VW said it believed that the £1.1 million paid was sufficient to cover taxpayer costs.

Mr Willis said: “I am in the process of preparing a reply to Ms Ellman.  I refute entirely any suggestion I intended to mislead the committee.  At each of my appearances before the Parliamentary Committees and in subsequent correspondence I have sought to answer all questions honestly and transparently.”