Monzo has denied that it unfairly froze customer accounts in the wake of accusations made in a BBC Watchdog report on Thursday night.

The BBC One programme criticised the start-up for freezing accounts without explanation, leaving some customers struggling to pay bills and buy food.

One mother told Watchdog: “It's been really stressful because it's put us into rent arrears; it's actually put a bit of a strain on our relationship as well. How do you explain to a four-year-old that there's no food in the house because of a bank?”

However, chief executive Tom Blomfield said on Friday that Monzo was no “more or less exposed than any other bank”.

He said Monzo could not tell customers why their accounts had been frozen because of a law that prevented banks “tipping off” customers to potential criminal investigations into their finances.

"The reality is we're opening about three million new accounts per year at the moment, which is a big fraction of all new accounts,” Mr Blomfield said.

“So we expect to see a big fraction of suspicious activity. I don't think we're out of line with any of the big banks.”