Two leading supermarket groups in the UK, Tesco and Safeway, have refused to back a campaign calling for a rise in the amount of land given over to organic farming.
The government has been petitioned by more than 100 organisations to set a target of 30% of UK agricultural lane set aside for organic production by the end of the decade, but the food retailing giants have declined to add their names to the petition.
Just 3% of UK farmland is currently organic, but the success of organic produce sold through stores such as Tesco and Safeway has led to a significant shortfall in supplies. As a result, 70% of organic food sold in the UK is imported from abroad.
Sainsbury's and Asda, the two other retail chains which top the British market, signed up to the Organic Targets Campaign, but market leader Tesco and Safeway declined to follow suit.
A spokesman for Tesco, which announced last November it wanted to increase sales of organic products to £1 billion within five years, said: "We are cautious about signing up to the campaign because we believe production should be market led. We also don't believe it is for us to dictate to government how the organic market should be taken forward."
Kevin Hawkins, spokesman for Safeway, said: "We are all for more organic produce but it has to be related to consumer demand and we think setting an arbitrary target for eight years hence doesn't make sense."
Other supermarket chains which have signed up to the campaign include Co-op, Iceland, Marks & Spencer, Waitrose and Booths.