Findings from the review, chaired by Sir Christopher Kelly, revealed that the group board failed to look after the bank and “badly” let down the group’s members.
Sir Christopher said: “The roots of the shortfall lie in a merger between the bank and the Britannia Building Society which should probably never have happened.
“Both organisations had problems. Bringing them together exacerbated those problems.
“It might have worked if the merged organisation had received first class leadership. Sadly it did not.”
The Co-op bank merged with Britannia on 1 August 2009.
In a statement posted on its website at the time the bank described the transaction as an exciting development in its history which would allow it to offer its customers and members “more than ever before”.
Kelly added: “”The lessons we set out are far from novel. It does no credit to those involved that they must be learnt again.
“I hope my report will help the group and the bank in their efforts to rebuild organisations of which their members and customers can once again be proud.”
