The organic body's report published earlier this week, found that Tesco, Asda and Safeway in particular were importing substantial amounts of organic food rather than buying from UK growers even when domestic supplies were in season. The report covered carrots, cauliflower, onions and potatoes in the fresh produce arena as well as beef, chicken and pork.

Retailers insist that there are several flaws in the survey carried out in mid-November to mid-December 2003. "The Soil Association's report is selective, unrepresentative and does a disservice to British organic farmers," said the British Retail Consortium's David Southwell. "By carrying out its survey before the UK growing season is underway and only asking its own members, the Soil Association is not giving a true picture of the amount of British produce sold through UK retail outlets."

But Soil Association policy director Peter Melchett said: "It is unacceptable for staple foods like cauliflowers and carrots to be imported when they are in season in the UK, and in plentiful supply."

The organic charity's survey was carried out by 1,000 of its own members visiting stores during the one-month period. They found that 13 per cent of Safeway cauliflowers were UK-grown and 19 per cent of Asda's onions. And although Sainsbury's - recently named the Organic Retailer of the Year - Waitrose and Marks & Spencer performed better, all three stores had areas of weakness. UK organic onions accounted for only 23 per cent and 41 per cent of the offer respectively at Sainsbury's and Waitrose, and M&S had the worst performance of all on potatoes with 58 per cent. "None of the supermarkets were consistently good or bad," said Melchett.

Asda was dismayed with the report. "We're selling more organic food than ever before," said a spokeswoman. "Ninety per cent of the food that can be sourced from Britain is. We think the Soil Association has been selective in the products highlighted."

The UK's leading retailer Tesco pointed out its strengths in the organic arena despite the report finding it only offered 55 per cent UK grown organic cauliflower. "We work very hard with our growers in the UK to increase the amount we source from them and we are very proud of our record," said a spokesman. "For example, in the UK season 100 per cent of our peppers, tomatoes and strawberries are grown in the UK. We are also dealing with very large volumes - much larger than some of the other supermarkets covered. We do import, but only when we can't get enough from the UK. For example, from next week we will have nearly 100 per cent UK organic cauliflower."

But while the Soil Association stresses that more organic sourcing is possible, Sainsbury's pointed out it has more than 40 per cent UK onions in store, not 23 per cent as quoted by the Soil Association.

The BRC, of which Sainsbury's is a member, was even more damning of the association's conclusions. "The BRC's own annual survey, which is provided by the government's organic action group disproves the conclusions of this selective report," said Southwell...."No one has done more than retailers to support and work with the British organic supply chain. We are disappointed that the Soil Association is yet again putting its own members’ interests above the welfare of the entire British organic sector."

The Soil Association has written to organic minister Ben Bradshaw asking him to raise the results of its report with the supermarket groups.