Co-op, the food-to-funerals operator, has been rocked in recent months after the former chairman of its bank arm, Paul Flowers, was arrested as part of an investigation into the supply of illegal drugs.

Finance minister George Osborne has ordered an inquiry into the bank, while Prime Minister David Cameron has questioned why Flowers, a one-time local Labour politician and Methodist preacher with no banking qualifications, was judged suitable for the chairmanship during a period when the bank nearly collapsed.

A 1.5 billion pound ($2.46 billion) capital shortfall at the bank has resulted in it falling under the control of U.S. hedge funds.

Myners was previously the Financial Services Minister in the Treasury. He has also held such positions as chairman of retailer Marks & Spencer, Guardian Media Group and Land Securities.

"The Co-operative Group has a long and proud history at the heart of communities up and down Britain," Myners said in a statement.

"Right now it faces serious challenges in terms of business performance and ensuring that the right governance is in place to deliver in the interests of all its members and customers."

Myners, who is a member of the upper house of parliament, will join the Co-op board as a senior independent director. He will also chair the board's current governance review, which is looking into how the group and the board is run.

The Co-op said it was also looking to appoint two additional independent non-executive directors to its board.

(Reporting by Kate Holton, Editing by Paul Sandle)