LAWYERS for Scottish car owners caught up in the Volkswagen emissions scandal are preparing to challenge the car giant in court before the end of the year if it continues to refuse compensation.

Patrick McGuire, a partner at Thompsons Solicitors, which is representing more than 250 motorists in Scotland whose vehicles were fitted with the "defeat device" software to cheat emissions tests, said the firm was now in the process of whittling down a handful of test cases in a bid to end what he described as a "Mexican stand-off" with the manufacturer over damages.

Car owners have been left outraged after VW offered US owners up to $10,000 compensation while refusing to make similar payments to customers in the UK and Europe.

The situation was described as "deeply unfair" by MPs, but the car maker insists it has faced "materially different" circumstances in the US compared to Europe - such as stricter regulations on nitrogen oxide emissions.

However, Mr McGuire said their position "made absolutely no sense" in law.

He said: "It seems that the time has come, and will come very soon in Scotland, to call their bluff.

"We are now actively looking at a client base to select a handful of test cases that we will be preparing for litigation over summer, because if things don't change it's really the only way that things can move forward."

Mr McGuire said Thompsons' clients - which includes Volkswagen owners as well as owners of the Group's other affected vehicles, such as Skoda and Audi - had recently begun receiving recall letters inviting them to bring their cars in for a "technical fix" which will bring them into line with European emissions standards.

He said that the results of this will be crucial in bringing their cases against VW, as it will allow engineers to assess whether there is any negative impact on running costs - such as reduced fuel efficiency - and crucially, whether owners suffer a drop in the resale value of their cars in the wake of the emissions scandal.

In a worst-case scenario for VW, Mr McGuire believes owners could be entitled to thousands of pounds per claim.

"The technical fixes haven't been done yet and when they are done we'll see what sort of impact that has as a matter of fact on the resale value of the cars," said Mr McGuire.

"I think it just stands to absolute reason, purely in terms of demand and supply economics, that there will be less demand for these cars and therefore the value will go down and that is directly caused by the activity of Volkswagen and, as long as we can establish that fact, then that will entitle people to damages."

He disputed the suggestion from VW that differences in the technical fix between the US and Europe exempted them from payouts here.

"That is illogical in the extreme, frankly. It makes absolutely no sense to me at all. The simple fact is that people, at the very least, will be put to an inconvenience and that will attract some level of fair compensation.

"At its base, we're talking about fraudulent activity by a manufacturer - call it what it is. Our consumer law serves to protect consumers as much as American law does."

A spokeswoman for VW in the UK said: "Our position has not changed on this and there is no buy back deal or compensation for drivers outside the US. That’s because the relevant facts and complex legal issues that have played a role in coming to these agreements are materially different from those in Europe and other parts of the world."

She added that regulations governing nitrogen oxide emissions limit were "much stricter" in the US than elsewhere, and that engine variants also differ significantly" in the US.

"This makes the development of technical solutions in the United States more challenging than in Europe and other parts of the world."