There are a number of issues that have to be addressed in our discussion. It is clear that a very large proportion of the public is opposed to the introduction of foods, feeds or agricultural products that have been modified using modern biotechnology.

If we are convinced that GM foods pose little or no risk to human health and to the environment, how do we convince others? How do we justify our conviction? If this conviction is based on comparison, why test if we don't test everything?

Why can we not test new GM-derived foods in the same way as we test new medicines? What are the constraints for testing foods which suggest that we should not apply the same standards as we insist on for pharmaceuticals. There are many answers, including the simple question as to what constitutes a dose.

Why is it acceptable to consider GM as a class, rather than discussing each modified product in relation to the changes made and possible predicted effects, trying to take into account indirect and delayed effects. We can be fairly sure that the products currently on the market have no immediate effect on consumers (or we would have already seen the impact). We have some evidence that the impact on the environment has been benign, if not providing an advantage – this evidence suggests that wildlife diversity has actually increased. Others speculate, based on laboratory experiments, that the delayed or indirect effects could be dreadful for the environment. Can we find any common ground?

When traits are introduced that have real changes on the way in which products interact with the environment, such as drought resistance, saline tolerance, modified oils, will not the blanket objection and therefore the blanket acceptance by scientists make the assessment more difficult and more dangerous?