Banks must today set out how they intend to keep themselves and their customers' money safe from cyber attacks as well as the type of IT chaos seen at TSB as part of a directive from the Bank of England.

Amy Pope, the former US Deputy Homeland Security Adviser to President Barack Obama who is now a partner at law firm Shillings, says the problem is prevalent.

"I can tell you from my work at the White House that we would see hundreds if not more attacks on the financial sector, and it ranges from the very unsophisticated - your so-called guy in his underwear sitting in his basement - to state actors and to highly sophisticated criminals."