“They may have jumped the gun,” says Puig. “Instead of continuing to argue the case for what they have done and working out a strategy with regulators for resolving that, they have engaged in these resignations.

“The fact that the chairman has had to come back tells us they have cut too far, too quickly,” Puig says. “They are now on life support.”

Brian Gardner, general manager of career management consultants, The Donington Group, says the board will immediately turn to interim executive recruiters for someone to step into the breach.

It is quite usual for a director – in Barclays’ case, chair Marcus – to step into the shoes of a suddenly departing CEO, Gardner says.

Gardner says the resignation of the COO suggest the board believes the situation of its leaders is untenable. “It looks as if there is a progression of discussions, which indicates the board is across the issues.”

However, Puig says history shows that when chairs step into leadership roles, it is often an “unmitigated disaster”. The roles are too different, with the CEO focused on operations and the chair on corporate governance.

The challenge for the bank now is to rebuild the trust of its clients, investors and employees, says Jarvis. “The main idea behind restoring trust is that it has to be earned. The last thing they need to be doing is pumping out public relations statements. They have to genuinely demonstrate they can be trusted, and it will take time – years.”

How can they do it? “By not putting shareholder value first and foremost, and making everything else secondary,” Jarvis says.

Says Puig: “The key thing now is who takes over the helm. What they need to do is bring in a CEO as quickly as possible so everyone can heave a sigh of relief. That person is calm, able to deal with inquiries, and with all the public facets. it is difficult to find a person like that, with sufficient gravitas to see this situation through.”

Gardner says Barclays may find a new CEO quickly if the bank looks in the right places. An interim executive recruiter might have someone ready to step into a permanent position. An internal appointment from the board or executive ranks is possible. In particular, an internal hire could step into the COO role, without it being called COO, while the bank focuses on the top leadership positions.

Barclays’ new broom must be a “Nelson Mandela” of banking, Jarvis says, referring to the integrity of South Africa’s first black president. “Whoever they put in will have to have a track record – a proven one – about having won the trust of everyone in the banking industry. They will not necessarily be eloquent and charismatic.”

“The problem is the board will say we need a fluent speaker. They will go for charisma, and that is not the issue. It is character.”