However, becoming a bank means it will be able to extend credit to customers via credit cards, overdrafts and mortgages.

“This means the stakes are higher for their customers if they’re targeted by a scammer,” says Rob Lilley-Jones.

“I think there might be a political element to Revolut’s licensing, because it’s becoming of a size to challenge High Street banks,” says Frances Coppola, a financial journalist and expert on banking risks and regulations.

“I think no government would want to have something of that size playing fast and loose with the rules.” However, she adds: “I suppose you could question, given there are so many complaints, whether Revolut should have a licence.”

The Treasury says the decision on whether to grant Revolut a banking license lies with the independent regulators. The regulators declined to comment to Panorama.

Revolut says that it abides by the same regulatory standards as any High Street bank, and it is sorry to hear of any instance where customers have been targeted by criminals.

It says it cut fraud by 20% last year but acknowledges “there is always more to do”.