A fresh bid to secure compensation for up to 46 million Mastercard customers is being revived.
A former financial ombudsman was seeking more than £14bn in a class action lawsuit against Mastercard claiming that its interchange fees – charges imposed on debit and credit card transactions – were anti-competitive.
Walter Merricks argued that the fees broke EU law in that they effectively resulted in consumers paying higher prices to businesses that accepted Mastercard between 1992 and 2008.
But the Competition Appeal Tribunal decided there was no way the case could go to trial as such a collective action could not guarantee any compensation would reach an individual, even if an illegal loss could be established.
Lawyers have now lodged an appeal against the ruling that blocked the case from heading to trial last month.
Mr Merrick said: “In essence this is a simple case. It has been conclusively established that Mastercard acted unlawfully and anti-competitively in imposing excessive credit and debit card fees.
“If I can establish the total amount of harm that Mastercard has caused to UK consumers, then why should consumers then get nothing at all if I cannot calculate the precise loss that each individual consumer suffered?
“Rather than allow consumer recovery, this would reward unlawful conduct by allowing companies to keep their ill-gotten gains,” he added.
Mastercard, which always insisted the claim had no legal basis, has until 8 September to respond to the appeal.
A spokesman said: “Consumers across the UK and around the world derive real value from Mastercard’s payments technology through the benefits of security, convenience and consumer protection.
“We believe that any appeal or review by Walter Merricks is without merit and that the Competition Appeal Tribunal’s judgment to refuse certification for the proposed collective action was the correct decision.
“Mastercard maintains that this claim is completely unsuitable to be brought under the collective actions regime.”