The court ruled that the Competition Appeal Tribunal (CAT) must reconsider the class action against Mastercard which it previously threw out.

The claim alleges 46 million people paid higher prices in shops than they should have due to high credit card fees.

The approval of the case marks the first mass consumer claim of its kind.

The case has been brought by former financial ombudsman Walter Merricks on behalf of all individuals over 16 who were resident in the UK for at least three months between 1992 and 2008 and who bought an item or service from a UK business which accepted Mastercard, BBC News reports.

Mr Merricks alleges that interchange fees led to UK consumers paying higher prices on purchases from businesses that accepted Mastercard.

Mastercard has said it “disagrees fundamentally with the basis of the claim”.

Mr Merricks’ original claim was dismissed by the CAT. The Court of Appeal said the CAT had applied the wrong legal test in making its decision, a ruling now upheld in a majority decision by Supreme Court judges.

If the £14bn is awarded and divided between the 46 million eligible people the payout would amount to £300 each.