A resurgant Aldi has opened a new front in its war with the supermarkets.

This week, the discounter launched its first range of Fairtrade products in time for Fairtrade Fortnight, which kicks off on Monday.

The five-strong range consists of organic bananas, tea, coffee and a dark and a milk Belgian chocolate. They are retailing at a premium to other Aldi lines, but at less than Fairtrade equivalents sold at the supermarkets.

Aldi's Fairtrade bananas, for instance, are £1.39 per kg compared with £2.09 at Sainsbury's, the world's biggest Fairtrade retailer. Its coffee is 10p cheaper, its pack of 80 tea bags 15p less and its chocolate is 99p per 100g bar, compared with Sainsbury's £1.32.

"We're committed to responsible sourcing as well as being focused on listening and acting upon feedback from our shoppers, who have told us Fairtrade is important to them," said an Aldi spokesman.

"We have kept the price low, which is part of our philosophy we just want to offer a great product at the best possible price, regardless of the range. These products are definitely ­premium quality."

Harriet Lamb, CEO of the Fairtrade Foundation, welcomed the new range. "We are very pleased to have Aldi on board, giving more farmers working in developing countries the chance to tackle poverty in their communities," she said. "The public have made it clear that they want to ­support those people for whom life is tougher."

Aldi and Lidl have enjoyed a comeback in recent months after developing their ranges and increasing their advertising. Aldi grew its market share from 2.9% to 3.1% in the 12 weeks to 23 January, according to Kantar Worldpanel.

Last week, it launched a fresh wave of TV advertising promoting the value credentials of its largely own-label offer against leading brands.

Datamonitor this week predicted global sales of Fairtrade food and drink would hit £1.3bn in 2014.