The Co-operative Group has been voted the most ethical firm over the past 25 years despite the scandal that has engulfed it over the past year.

The Co-op, which sank to a £2.5bn loss in its last financial year, was ranked the top firm in a survey to Ethical Consumer magazine readers.

The accolade comes as the funerals to food group attempts to reform the way its run after its bank was hit by a £1.5bn blackhole and its former chairman Paul Flowers was accused of taking Class A drugs.

Former Co-op chief executive Euan Sutherland quit after his salary details were leaked by the board and slammed the group as “ungovernable”.

However, the mutual’s board is attempting to devise reforms that will win support from its members, with a special meeting expected to take place next month.

Ethical Consumer co-director Tim Hunt said: “Many commentators have had their knives out for the Co-op Group in recent months. Ethical Consumer’s readers, however, are able to see through the spin and realise that despite the problems the Co-op remains an ethical business at heart – at least for the time being.”