Sainsbury's has announced its sales growth in Fairtrade bananas is outstripping conventional bananas three to one.

The retailer said one in four of the bananas it sells is Fairtrade certified, while overall Fairtrade banana sales are growing by 27 per cent a year.

Sainsbury's is also set to be the first supermarket to sell Fairtrade bananas free of all packaging, rendering them more environment-friendly.