Supermarket price wars are forcing Fairtrade growers away from the UK retail sector and into new, overseas markets, the Fairtrade Foundation has warned.

Bruising competition and aggressive pricing tactics on a range of products - including fresh produce such as bananas - was turning the UK into an unviable market for some growers, said its commercial relations director Ashish Deo.

“If you want people to work with you in creating a more sustainable product, you need to be a good customer,” he said. “These growers have expectations they have to meet regarding quality and sustainability, but it’s hard to get people to meet those expectations if the retailer is not paying the appropriate price.”

At the same time, growing demand for Fairtrade products in other parts of the world meant the UK and Europe were becoming less important markets for Fairtrade growers, Deo added.

“There is a limit to where costs can be cut, and a limit to how much pain these growers can bear,” he said. ”retailers need to address these unsustainably low prices, so that there is room to pay the right price and the right wages.”

Deo’s comments follow the Fairtrade Foundation’s publication in March of Britain’s Bruising banana Wars. In the report, it claimed production costs for growers had soared while retail prices had fallen, with UK consumers paying an average of just 11p for one loose banana compared with 18p a decade ago.

But Andrew Opie, director of food and responsibility at the British Retail Consortium, said retailers understood the need to work in partnership with growers. “Retailers know you only develop long-term supply chains by paying a sustainable price. As bananas are so popular with customers, it would be mad not to.”