Genetic modification technology is a great research tool but it's crude. Some scientists claim that GM is just an extension of natural evolution, a development of cross-breeding, but this is, technically, totally inaccurate. The way genetic modification has been used to manufacture GM crops causes thousands of changes in the DNA of the plants' cells, variations of a different quality and quantity to cross-breeding.

Some of these are benign, but some are going to disrupt one or more functions of the plant. So it may now be herbicide resistant, but unable to stand heat, its nutritional value may be lowered, known toxins increased, or even new toxins introduced into the plant.

This mutagenic effect is well known, research by the Food Standards Agency has found such disturbances in the patterns of gene function, but at the moment we are being too selective about what we are looking for, so the health consequences are completely unknown. The risks of releasing genetically modified organisms into the environment are widely accepted.

In the research I do using genetic modification there are regulatory requirements that Genetically Modified Organisms (GMOs) are only used in "contained use" conditions and are genetically crippled, so they cannot escape and interact with the environment. It's totally bizarre that these rules do not apply for the same kind of technology used in GM crops. What we are seeing here is the irresponsible releasing of GMOs in to the environment with unknown consequences. GM crops are not performing as expected: GM cotton suffered cotton ball and root problems while GM soya has shown consistently lower yields than non-GM equivalents.

And animal feeding studies have shown the potentially damaging effects of soya, maize and potatoes. GM potatoes have caused intestinal lesions; GM soya has caused liver cell changes and premature death in the young; GM maize has caused problems with the kidneys and the blood system. Mechanistically, we do not know why this is happening or what the consequences for human health are, but there are clear physiological changes that have been recorded. Once out there we cannot contain it.

We don't need GM crops. Crop genetic diversity is enormous and can be exploited through natural cross-breeding aided by modern genetic screening technologies. The problems we have in agriculture are social and political. What is driving GM crops is economics.