In principle farmers grow what consumers demand. In between them are food processors and retailers. Some of them have massive market power and their requirements actually shape the market. This is also the case for GM food: Most European supermarkets and big brands require GMO free quality and made respective commitments to their customers. In many cases they have been pushed by their customers and NGOs to take this position.
Lindsay Keenan, Greenpeace
Keenan: Consumers keep food processors and retailers GM Free
Lindsay Keenan: EU Markets report on GM food
COOP -Italy: Position on the use of genetic engineering in the agroindustrial filed
COOP - Italy: Position on Genetically Modified Organisms in nutrition