Environment secretary David Miliband has sparked controversy after claiming there is no proof organic food is healthier than ordinary produce.

“It's a lifestyle choice that people can make. There isn't any conclusive evidence either way,” he told The Sunday Times.

“It's only 4 per cent of total farm produce, not 40% and I don't want to say that 96% of our farm produce is inferior because it's not organic,” he added.

The Soil Association insisted there was a difference between organic and ordinary food, while Peter Kendall, president of the National Farmer's Union, said organic was “a great opportunity” for farmers.