Whingeing Co-op chief executive Euan Sutherland resigned yesterday after less than a year in the post, plunging the troubled bank into crisis.

The fat cat's decision to quit followed his Facebook attack on Co-op board members after details of his £3.6 million bonus were leaked to the press.

Mr Sutherland was to pocket the bumper payout despite the former mutual planning to axe and 5,000 jobs and being £2 billion in debt.

In the Facebook post on Sunday, he ranted that the story appeared to have come "from our group boardroom" and moaned that some members were "determined to make life difficult and embarrassing."

Mr Sutherland yesterday blamed the group's egalitarian policies for his resignation.

The resignation, and the early release of details from Lord Myners's governance review, prompted members to provisionally agree to a new leadership structure.

The 21-member board will be abolished and replaced by a dual structure including a new PLC-style board including only executive and non-executive directors, responsible for taking commercial decisions.

Those elected from the group's membership will sit on a parallel board to safeguard its traditional values.

Critics agree on the need for change but they are clear that the core of the Co-op's problems stem from disastrous forays into the financial sector, rather than its democratic structures.

Cooperatives UK vice-chair Nick Matthews said Mr Sutherland was a "PLC man to his fingertips" and said his sudden departure was a "culture clash."

Mr Matthews said: "In the co-op retail sector we do need radical reform but reform that everyone can buy into.

"The problems that have occurred in the bank and in other parts of the business have been caused by an overpowerful CEO, not by the members' democratic scrutiny of strategy."