Fairtrade sales are being hampered by a lack of consumer understanding of the concept, according to Peter Marks, chief executive of The Co-operative Group.

Speaking at an AgroFair seminar last week, he said customers would be much more likely to buy Fairtrade if there were a better explanation of the benefits to the African growers.

"The whole Fairtrade concept needs to be promoted, because people understand Fairtrade is good but don't understand what it means," he said.

"That message must be got over by suppliers, retailers and government in a much more powerful way. It has to be made more meaningful."

If consumers knew that choosing a Fairtrade banana over a non-Fairtrade one could mean an African family could have running water or send its children to school, they would be more likely to select it, said Marks.

Fairtrade sales in the UK grew 70% last year to nearly £500m, according to the Fairtrade Foundation, but Marks said he felt it could go further.

Quality was also fundamental to the long-term success of the mark, he added. It was not enough to build long-term sales simply on the concept alone.

While supermarkets had a key role to play in Fairtrade's future, they still had to make a firm commitment to the concept, he added.

"Retailers must prove their support is not just a short-term response to an opportunity," he insisted. "The pressure is on retailers to demonstrate that ethics is part of their DNA and not just a fad."

Marks also said he did not believe the credit crunch would impact sales. "Despite the doom and gloom I still believe Fairtrade is here to stay."

The Co-operative Group has been accelerating its rollout of Fairtrade products this year, and is now carrying more than 200 lines generating sales of £60m. Marks promised further new product launches later this year.