Millions of Visa or Mastercard users have been issued a warning over new charges.

British customers face new EU shopping fees after firms have increased so-called interchange fees for online credit and debit cards for UK to EU transactions.

Fess have been increased from 0.2% to 1.15%for debit cards and from 0.3% to 1.5% for credit card transactions.

The Treasury Select Committee addressed the issue on Thursday as MPs have written to Visa and Mastercard to find out why the price hikes have been introduced.

Committee chairman Mel Stride, said: “Recent rises in the fees paid by firms for cross-border debit and credit card transactions add additional costs to businesses, many of whom are already grappling with rising inflation and other cost pressures.

“That’s why we have today written to Visa and Mastercard to request an explanation for these fee increases.”

In a letter to the firms, Ms Stride said: “The committee is aware that the EU Interchange Fee Regulation and the UK Interchange Fee Regulation which cap consumer debit and credit cards at 0.2% and 0.3% respectively no longer apply to cross-border interchange fees.

“However, the Payment Systems Regulator has informed us that it has not seen ‘evidence that shows that there have been significant changes in the costs for issuers of enabling online transactions via EEA-issued cards in the UK, or UK-issued cards in the EEA.”

The letter continued:  “I would therefore be grateful if you could write to us with the underlying reasons behind your increase in cross-border interchange fees.”