Up to 600 million GM crop plants could grow in Britain annually under plans drawn up by the European Commission to be considered next week.
The plans would in effect bring in GM agriculture by the back door, and seriously compromise organic farming across Europe. They could lead to European farmers growing more than six billion genetically modified crop plants every year, without realising it.
British ministers will decide this week whether to back the plan at the meeting, and their verdict could be decisive. Britain has so far supported it - but ministers are now reassessing their position in the light of accumulating evidence about the hazards of GM crops. Results of the Government's official trials reported last week that growing GM oilseed rape and sugar beet would harm British birds, butterflies and other wildlife much more than conventional cultivation.
Other government reports concluded that growing the sugar beet could drive the skylark to extinction within two decades, and that just one season of the oilseed rape would contaminate the countryside for more than 16 years.
Both crops are now likely to be banned in Britain but this ban could be negated by the European proposal, which recommends contamination levels of up to 0.3 per cent in rape seed, 0.5 per cent in maize, sugar beet, tomato and potato and 0.7 per cent in soya.
These apparently tiny figures, experts say, would lead to the widespread growing of GM crops, even by organic farmers. They would mean that one in every 200 apparently conventional or organic maize or sugar beet seeds, could in fact be GM. Seed packets would not have to mention the contamination unless it had been deliberately introduced.
Organic and conventional farmers, Greenpeace statistics show, would be unwittingly growing up to 4.5 billion GM oilseed rape plants, and up to 2.3 billion GM sugar beet across Europe every year. As their genes inevitably spread, critics say, the problem would get worse, even making organic agriculture impossible.
Michael Meacher, Environment minister for six years until his sacking this summer, said yesterday: "This would introduce GM by the back door and behind the backs of the people of Britain and Europe."