Quinn Emanuel Urquhart & Sullivan and Freshfields Bruckhaus Deringer are making the final preparations for next month's U.K. Supreme Court hearing in the major £14 billion Mastercard saga, which will proceed via videolink.

The case, which is set to play out its final phases in the Supreme Court on May 13, is according to people close to the matter, likely to be a precedent-setting case that will have significant consequences for subsequent civil cases.

The hearing will take place by Webex videolink, according to a person involved in the matter, in view of the lockdown imposed amid the COVID-19 pandemic. The parties have also been in regular contact with clients using WhatsApp, according to one person close to the matter, as technology plays an increasingly pivotal role in court matters.

This week, lawyers at Quinn filed their case with lawyers at Freshfields, in the latest step ahead of the appeal hearing next month.

The credit card giant stands accused of inflating interchange fees – a sum charged between Mastercard and banks – which was then passed on to traders using card machines, and in turn onto consumers. It faces a potential consumer collective action brought by Quinn client and former financial ombudsman Walter Merricks on behalf of around 46 million consumers for damages of £14 billion.

The claim, which purports to account for overcharges over a 16-year period between 1992 and 2008, would, if successful, result in the U.K.'s highest ever damages payout. Merricks and his team have since 2016 pursued what would be the U.K.'s first major 'opt-out' action, ushered in by the Consumer Rights Act 2015, by which all relevant U.K. consumers could be party to the action and receive a share of the payout, unless they opted out.

The case has seen Quinn and Freshfields trade blows since 2017, when, siding with Mastercard, the Competition Appeal Tribunal halted the potential collective action. However, exactly a year ago today, the U.K. Court of Appeal set aside the tribunal's ruling, finding that it had "applied too high a bar" as it made findings on how damages might be distributed, the person involved in the case said. For Quinn, it was a significant, albeit short lived, victory, as Freshfields late last year won the right to appeal the decision at the Supreme Court.

Next month, the Supreme Court will start by considering two main issues, the partner said. First, the legal 'certification test' that the Competition Appeal Tribunal must apply in deciding whether or not to allow proposed collective proceedings to go forward. And second, whether the tribunal is entitled to take account of whether any distribution of damages to members of the proposed class would bear any relationship at all to the tort law principle of compensatory damages.

Acting for Mastercard, the Freshfields team is being led by global antitrust litigation co-head Mark Sansom and senior associate Ricky Versteeg, with support from Mark Hoskins QC, Hugo Leith and former Freshfields partner Jon Lawrence of Brick Court Chambers, and Matthew Cook of One Essex Court.

Quinn, meanwhile, is deploying a team fronted by partners Boris Bronfentrinker and Nicola Chesaites, and senior associate Leo Kitchen, with a counsel team comprising Paul Harris QC of Monckton Chambers, and Marie Demetriou QC and Victoria Wakefield QC of Brick Court Chambers.

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