The Co-operative Group has "acknowledged its governance is not up to scratch", Lord Myners said following members unanimously voting for reforms.
Lord Myners said: "I'm thrilled with the outcome today...there has been a fundamental change in position".
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The Prime Minister will urge leaders of the other 27 EU states to move on as quickly as possible to talks on Britain's future trade.
Despite temperatures reaching double figures in the south today, it was still a chilly day, with brisk winds.
The four-time Tour de France winner has said he has always taken great care to stay within the rules after returning an adverse urine test.