It follows a crisis last year when it nearly collapsed and had to be rescued by investors including US hedge funds after a £1.5bn hole was found in its balance sheet.
The wider Co-op group now has a stake of just 20 per cent in the business, loosening the lender’s connection to the 150-year-old mutual organisation which previously owned it outright.
But the bank’s chief executive Niall Booker insists that its ethics continue to be central to its identity.
He said: “The Co-op is not like other banks. Our heritage, ethos and values are different.
“That is why it is so important to renew and refresh our values and ethics to ensure that the next chapter of the bank is true to its heritage and translated to today’s world.”
The poll of 4.7 million personal and business customers will seek views on the five elements of its current ethical framework: human rights, international development, animal welfare, economic and social development in Britain, and the environment.
The survey will also gauge opinion about three new areas: responsible banking, transparency and treating customers fairly.
Results will feed in to a new ethical policy to take effect from this autumn.