Tesco has pledged to refund customers after it emerged thousands have been charged twice for their shopping.

A glitch in its payment system means some shoppers paying by debit or credit cards have had the money taken out of their accounts twice.

Finance website MoneySavingExpert.com said it had seen complaints dating back to February 6, and stores affected include branches in King's Lynn and Newmarket.

Tesco refused to confirm locations, saying only the issue was affecting stores across the UK. It also would not comment on how many duplicate payments it had processed.

In a brief statement, the supermarket chain added: “Due to a technical error some customer card payments have been authorised more than once.

"We’re sorry for any inconvenience this may have caused, and we want to reassure affected customers that they will only pay for their purchases once and any duplicate transactions will be reversed.”

The problem is understood to occur after some customers have entered their card details again after seeing an error message at the till. They believe the original transaction has not gone through and are then charged twice.

Furious customers have taken to social media to lambast the store giant.

One tweeted: "Bought £70 worth of shopping and £20 worth of petrol, not content with taking it once they’ve taken BOTH transactions twice. That’s called stealing whichever way you look at it. Thanks for leaving me short."

"This is not on. Do I help my self to extra food off the shelf? No I don’t. Stop double dipping my bank account."

Tesco said those affected would have the payments reversed automatically. But while money is taken instantly when you pay for shopping, funds can take a week or more to be returned to your account.