Pester was hauled before the Treasury Select Committee for the second time earlier this week, where he faced a grilling from MPs about the ongoing problems at the bank.

Pester's arrival in the hot seat was preceded by evidence given by FAC chief Andrew Bailey, who intimated that the bank boss had sugar-coated the scale of the problems at the bank and flagged up reports of over 10,000 fraudulent alerts in the wake of the breakdown as criminals took advantage of the chaos.

Pester admitted to the Committee that the volume of attacks were 70 times the normal level, overwhelming the bank's ability to respond. He says he was shocked at reports of customers waiting up to nine hours to speak to a member of the bank's fraud department and has since installed a dedicated fraud hotline. In total, 2200 customers had experienced attempts to access their accounts, and 1300 had suffered actual financial losses.

Reflecting on the evidence, the Committee has written to TSB chair Richard Medding, stating: "The Committee considers that the TSB Board should give serious consideration as to whether Dr Pester’s position as chief executive of TSB is sustainable. The Committee has lost confidence in his ability to provide a full and frank assessment of the problems at TSB, and to deal with them in the best interests of its customers. It is concerned that, if he continues in his position, this could damage trust not only in TSB, but in the retail banking sector as a whole. I ask that the Board consider the Committee’s view as a matter of urgency."

Medding responded to the Committee's stinging rebuke by saying that Pester continues to have the full support of the Board.