Drivers left fuming after buying a Volkswagen diesel car that pumped out more pollution than advertised could pocket £1,000s in compensation by joining a 'class action' that may end up costing the motoring giant billions.

The lawsuit relates to the 2015 VW emissions scandal in which the German carmaker admitted 11 million diesel vehicles worldwide – including 1.2 million in the UK – were fitted with software to cheat emissions tests.

It meant consumers were paying extra for VW diesel vehicles (also including Audi, Seat and Skoda brands, part of the VW Group) that they believed were more environmentally friendly, but in fact the NOx emissions (a combination of pollutants nitrogen oxide and nitrogen dioxide) produced by the cars in question were far higher than the company stated.

VW is subsequently involved in lawsuits in several countries and has already agreed a $15 billion (£12 billion) settlement with US authorities and owners of affected vehicles.

Now law firm Harcus Sinclair says it's taking the case against VW to the High Court on behalf of 10,000 affected UK consumers who have signed up to take part. It estimates the average payout to past and present owners of an affected vehicle will be in the region of £3,000. However, it's important to note there's no guarantee the class action will be successful and VW has vowed to "defend such claims robustly".

Rival law firm Leigh Day says it has also been approached by 10,000 VW owners regarding the issue – though it's not launching a class action and has instead opted to submit two test cases to dispute resolution body the Motor Ombudsman.

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How do I know if I'm eligible to join the VW emissions class action?

The first point to make here is that not all cars manufactured by the VW Group are affected by the emissions scandal. These are the criteria your car must meet for you to be eligible:

  • Your car is/was a VW, Audi, Seat or Skoda
  • It has/had a 1.2, 1.6 or 2 litre diesel engine
  • It was made between 2009 and 2015
  • You purchased, leased or acquired it (new or second-hand) before 1 January 2016

If you're able to tick off all of the above then you may be able to take legal action against VW by joining the class action.

If you choose to sign up to the class action, you'll be represented by Harcus Sinclair and Slater and Gordon, which are leading the action against VW. Once you've provided your details (including the necessary information about your car) the lawyers will proceed with the case on your behalf.

There's no cost to join the class action, but it will proceed on a no-win, no-fee basis. That means if it's unsuccessful there's no cost – but if it's successful, 30% of the compensation you're awarded by the court will be taken to cover legal costs.

How many people will be eligible to sign up?

Approximately 1.2 million cars in the UK are affected by the VW emissions scandal, which means at least that number of people should be eligible to join the class action. The actual number of eligible claimants will most likely be far higher than 1.2 million, as many of the affected cars will have had multiple owners.

How much do I stand to make in compensation?

If you have, or previously had, an affected vehicle the likelihood is that you overpaid for it – and the resale value may also be affected. This is one of the reasons Harcus Sinclair is encouraging people to join its class action.

The figure being touted in terms of how much compensation claimants will get if the action is successful is £3,000. However, that figure could be considerably higher for those who paid significantly more than they should've for their car.A spokesperson for Harcus Sinclair told us the £3,000 figure was a "conservative estimate" and said there have been cases in the US where claimants received between $8,000 and $10,000 (£6,600 and £8,250).

But remember that to get anything the lawsuit would have to be successful, and there are no guarantees. If the lawsuit fails, you won't get anything.

Was your car affected by the VW emissions scandal? You could claim £1,000s by joining lawsuit (if it wins)
NOx emissions cause 23,000 premature deaths in the UK each year, according to Government figures

What happens next?

An application for a 'group litigation order', which is the first step in the legal process, is being heard at the High Court on Monday 30 January.

While there's no official deadline for joining the class action, Harcus Sinclair is hoping to have most claimants signed up within six months of the initial hearing, as it wants "a quick resolution for UK consumers".

The law firm expects the case to go to trial within the next 18 months – so, providing the class action is successful, it's likely to be at least a couple of years before claimants receive any money.

What about Leigh Day's case?

Leigh Day is another law firm taking up the issue – but rather than launching a class action, it's submitted two test cases to the Motor Ombudsman.

While it's currently focused on its two test cases, Leigh Day told us affected car owners are able to approach the firm and register their interest in having their own cases submitted to the Motor Ombudsman in future. If the firm later chooses to submit your case, it'll be on a no-win, no-fee basis.

What does VW Group say?

In a statement, the company said: "We have been notified that Harcus Sinclair intends to bring proceedings against Volkswagen on behalf of 77 claimants in the English High Court in relation to the NOx emissions issue. As we have previously said, we intend to defend such claims robustly. We haven't received the claim yet, so we cannot comment further."

Responding to the quote, Harcus Sinclair told the 77 figure was an old number and it has now signed up 10,000 people to be part of its class action.