The Soil Association believes there is a consumer-led backlash against genetically modified food and has hailed a "non-GMO" labelling initiative as the beginning of the end for GMs.

The label will be launched by more than 400 American processors and retailers next year and has the backing of presidential candidate Barack Obama.

About 28,000 products will be labelled by the companies, which have a combined worth of $12bn.

The Soil Association's policy director, Peter Melchett, told Farmers Weekly: "Labelling stopped consumers buying milk from cattle treated with the growth hormone rBGH, leading Costco, Kroger, Publix, Safeway and Wal-Mart to turn to non-GM own-brand milk.

"It is the 'beginning of the end for GM worldwide'," Lord Melchett said.

The rBGH developer, Monsanto, is now selling off the hormone, he added.

Lord Melchett said a Soil Association survey provided further evidence of opposition to GMs.

It showed that more than half of American consumers would not eat food containing genetically modified ingredients.

Given the choice, 53% of those surveyed said they would not eat GM products while 87% Americans believed food should have its GM content labelled, the survey suggested.

At the same time, he argued, farmers were rejecting GM crops. "European farmers have been being told to turn to GM for two decades because 'American farmers love GM'", he said. "

But look at GM alfalfa - US farmers got it banned in courts because it makes weeds resistant to pesticides."

Lord Melchett said that the Soil Association is: "Not anti-yield and not anti-technology". He advised farmers to look to other technologies instead of "old-fashioned" GM.