Across the continent, credit and debit card issuers revel in profit margins of up to 65 per cent and 47 per cent respectively, the report finds.

“In quite a few member states, the users of those services are being ripped off,” commented Ms Kroes, vowing to take “appropriate enforcement action” against those firms setting “unjustifiably” high fees.

The findings will compound anxiety over the profits credit card lenders make from their fees, including VisaEurope and Mastercard which are currently the subject of an investigation by the Office of Fair Trading (OFT) for violating competition guidelines.

The OFT must “press ahead quickly to bring an end to the anti-competitive behaviour that has gone on far too long,” Kevin Hawkins of the British Retail Consortium told the Guardian.

The credit and debit card market in Europe is worth €1,350 billion each year and serves 500 million banking customers across the EU.

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