The Guardian claims that a report to be published next week by the Philosophical Transactions of the Royal Society, which looks at the results of three years of field trials - the largest experiment on GM crops in the world - will conclude that two of three GM crops grown experimentally in the UK are harmful to the environment.
The report is likely to increase tension between the USA, which has already started using genetically modified crops in a big way, and Europe, where consumers are generally much more concerned about the use of GM crops and have pressured governments to take a cautious approach to the use of GM plants.
Fields on which the GM crops were grown showed a marked reduction in the bio-diversity (i.e. the number of weeds and insects) present, compared to fields growing non-GM crops. Both GM and non-GM crops were sprayed with herbicides during the trial and it is presumably the necessary use of the herbicides combined with the presence of the GM crop that causes the change in the balance in ecosystem.