Earlier this week Tesco joined other major supermarket chains by dropping the assurance that its poultry should be fed non-GM feed. The supermarket claims that due to a shortage of non-GM soya — the key ingredient in chicken feed — it was no longer able to guarantee that its chicken would be GM-free. It ends more than a decade-long ethical commitment, and follows Asda, Sainsbury’s, Marks & Spencer and The Coop. Waitrose is the only supermarket to continue a commitment to a non-GM policy.

Tesco’s claims were disputed by Soil Association Policy Director, Peter Melchett, claiming that “in Brazil alone, there is enough non-GM animal feed to supply the whole of Europe.”

In a letter to Tesco customers published on 12 April, Technical Director Tim J Smith said: “It is a global supply issue – 80% of the world’s soya is now modified.” Cost and competition could be a likely factor in the decision, for example, Defra figures show a rise of 25% in the cost of non-GM feed over the last two years.

Tesco, Asda, Sainsbury’s and Morrisons have all highlighted that their organic ranges are still available to customers who sought an alternative.

The Soil Association is now calling for clear and honest labeling on all food from animals fed on GM feed in the UK.