The organisation is slashing the price of Fairtrade bananas in a bid to bring the concept into the mainstream.
The three-week half-price promotion, which sees prices drop from £1.70 to 85p a kilo across all 2,400 stores, has been designed to raise the profile of Fairtrade by encouraging shoppers to sample the fruit.
The Co-op Group estimates selling more than two million Fairtrade bananas a week during the promotion, which started on Monday.
The fruit is being imported by AgroFair under the Oké brand from plantations in Colombia, Costa Rica, Ecuador, Ghana and Peru, and the Co-op Group is bearing the cost of the promotion along with help from AgroFair and suppliers Fyffes and Chiquita.
Duncan White, a director with AgroFair, said: “We are delighted to be involved with yet another Fairtrade first - the result of the determination and hard work of our farmers and the inspiring, fresh ideas from the Co-op.”
The Co-op Group’s marketing development manager Brad Hill said: “The aim is to bring Fairtrade bananas to a wider consumer base and create tremendous awareness of Fairtrade generally.
“We hope to encourage as many customers as possible to continue to buy Fairtrade bananas and seek out other Fairtrade products.”