Or ask the thousands of Spanish, German and French farmers already growing GM varieties of maize whether they should be banned from doing so and you will receive a very clear answer. And they are, relatively speaking, the rich ones. Of the world's 12 million farmers, more than 90 per cent are regarded as "resource poor" and derive more than 80 per cent of their income from farming. For them, GM crops have the potential to transform their lives for the better. We cannot deny the millions of people who might benefit from this science by demanding that it be stopped, as Prince Charles is doing.