Co-operative critic joins troubled group's board.

Sir Christopher Kelly said the group had badly let down its millions of members by its failure to provide "proper stewardship" to the lender, which was dragged down by its disastrous merger with the Britannia building society.

Now the former Treasury mandarin has been named senior non-independent director of the food-to-funerals group, the first external appointment under radical governance reforms drawn up in the wake of the debacle.

Sir Christopher will help recruit members for an entirely new board which will be in operation from next May.

Group chair Ursula Lidbetter said: "Sir Christopher's recent report into The Co-operative Bank was detailed and incisive and was instrumental in helping us move on by learning from the mistakes of the past.

"His deep experience of finance, public policy and governance mean that he is ideally suited to the new role of senior independent non-executive director."

The group also named Simon Burke as independent non-independent director. He holds a similar role at the BBC and has previously been non-executive director of Co-operative Food.

The slimmed-down board marks a radical change from the way the Co-op was previously run by elected directors - including a plasterer and retired deputy head teacher - but will now largely consist of professional business people.

Reforms were approved by the group's membership following a coruscating report by former City minister Lord Myners who said it was apparent that none of the board could handle the complex issues faced by the debt-laden and crisis-hit business.

Sir Christopher's report had also been scathing about the group directors.

He said: "I have no doubt at all that the methods used over the last few years to appoint members to the board of the Co-operative group and its subsidiaries have led to serious failures in relation to oversight and governance of the bank."

The group suffered the worst crisis in its 150-year history last year as it notched up a staggering £2.5 billion annual loss after being dragged down by the near-collasps of the bank.

It now owns just 20% of the lender, following a rescue which saw bondholders including US hedge funds take majority control.

The group has also weathered the departure of chief executive Euan Sutherland, who walked out earlier this year claiming it was ungovernable as he tried to push through reforms.

But his successor Richard Pennycook said in September that the business was now ready to rebuild its shattered reputation as it reported comprehensive income of £116 million for the six months to July 5, up from a £1 billion loss a year before.