The two US giants are being sued on behalf of hundreds of merchants over the multilateral interchange fees charged for accepting card payments.

Having initially declined to certify the cases, London’s Competition Appeal Tribunal has now given the green light for revised applications to proceed.

The decision is the latest development in a long-running series of suits over the fees Visa and Mastercard charge merchants.

Commercial litigation law firm Harcus Parker is bringing the case on behalf of UK businesses in a case that could seek at least £7.5 billion in compensation.

Last month, the Payment System Regulator stepped back from imposing financial penalties on Visa and Mastercard scheme and processing fees, despite evidence that the firms are running an effective duopoly in the supply of services to merchants.