Former City minister Lord Myners has laid out his plans for saving the Co-op with a final broadside to traditionalists "still stuck in denial" over its failings.
He admits he is "less confident" the group will choose the radical decisions he believes are needed to overhaul the current deficiencies in governance at the ailing mutual, which last month reported annual losses of £2.5 billion.
The basis of his proposals, which include the abolition of the group's 21-member board to be replaced by a slimmed-down body to take commercial decisions, will be put before the Co-op's AGM in Manchester on May 17.
But regional membership boards and independent societies that currently hold sway in the group are reported to be unhappy about the proposals.
In a damning report of the way the group is run, Lord Myners said: "Radical decisions on governance structure need to be taken very soon - and with resolution - if the Co-op, as my mother knew it, is to be saved.
"The decision lies in the hands of the elected democrats. I have done all I can do."
The report comes days after the running of the food-to-funerals mutual was sharply criticised in a review by Sir Christopher Kelly into the near-collapse of its banking arm - a report which backed the need for change.
Lord Myners, who recently resigned as a director after just four months, said that the 15 lay directors on the current board were drawn from a total eligible pool of only 35 regional board members. They include an engineer, a plasterer and a retired deputy head teacher.
He said that apart from the lack of relevant skills and experience, "this has not even been genuine democracy at work".
The former chairman of Marks & Spencer said: "I have no doubt that the Co-operative Group can over the next five years reverse a decline that started over 50 years ago. But I am less confident that it will choose to do so.
"Much will depend on the small number of 'elected democrats', less than one in 10,000 of the group's entire membership.
"Will they put their self-interest to one side for the greater good, acknowledging the collective failure of the current board and the crippling deficiencies of the entire governance system?"
"I would say that the group board and many on the regional boards are still stuck in denial over this near ruinous failure of governance, whereas the vast majority of ordinary members feel justified anger."
Lord Myners said the resistance from traditionalists reflected a culture of entitlement within a small but highly active proportion of the membership.
He added: "This has undoubtedly created strong vested interests and a reluctance to rethink existing ways of doing things.
"I have myself witnessed repeated instances where there has been denial of responsibility, corrosive suspicion, deliberate delay and a practice of hiding behind 'values' in order to deflect or stifle criticism and protect self-interest."
In the report published today, Lord Myners' proposals for reform include:
:: The creation of a new group board made up of an independent chair with no previous association or involvement with the Co-op, six to seven independent non-executive directors and two executive directors. The non-executive directors will have the skills and experience of directors sitting on the boards of the group's primary competitors.
:: The establishment of a National Membership Council (NMC) of about 50 individuals, including around 10 employees. The NMC will elect from its membership a steering committee of 12 which will also include representation from independent societies.
:: A nominations committee to screen and propose candidates for group board approval and for election and re-election by members at each AGM. The committee would comprise five non-executive members, including up to two representatives designated by the NMC.
:: The review will also seek to extend constitutional rights to the entire membership of the group. The "one member, one vote" has been a core principle of co-operative ownership, but Lord Myners said at present ordinary members have very little power. All members will have the right to elect board members, the right to attend meetings and to approve significant transactions.
Lord Myners said: "There is no short cut to recovery from its present weakened state. It will require retrenchment and some painful choices.
"After 150 years of development, and an extended period of financial decline, the organisation has seen more than half of its net assets wiped out in the past five years. Financial health can only be restored through steady, step by step, rebuilding of the group's profitability and repayment of its excessive debt."
Ursula Lidbetter, chairman of the Co-operative Group, said a resolution containing four key principles on reform will be put to members at the AGM.
She added that the board of the group has made clear its "commitment to far-reaching and fundamental reform of our governance".
Ms Lidbetter said the Myners report was an invaluable contribution as the board looks to put the right changes in place: "As group chair, I see this as essential and urgent work that is critical to our future, enabling us to build a more effective organisation which can deliver for all our members, customers and colleagues."
Britain's largest union Unite described the report as the "only game in town", which could deliver a future for the group and its workforce.
Last month the union wrote to Co-op's regional board members on behalf of its 1,200 members urging them to back reform.
Unite national officer Adrian Jones said: "The current situation is unsustainable and recent events should leave people in no doubt of the need for reform to secure jobs and the Co-op Group's future.
"Our members embrace the Co-op's unique ethos and have been working tirelessly to make the group a success, but they are increasingly feeling frustrated that their livelihoods are being overlooked in the internal power struggles over whether to reform the group."
Unite has more than 1,200 members working for the Co-op Group based mainly in logistics.