Environment secretary Margaret Beckett has permitted the planting of GM maize, but legal challenges, qualifications and scientific questions remain.

Mrs Beckett told parliament that the government would oppose the growing anywhere in the European Union of the two other GM crops involved in the recent tests, known as the farm-scale evaluations, beet and oilseed rape.

She said the GM maize licences would expire in October 2006, and any consent holders wishing to renew them would have to carry out scientific analysis during cultivation. Beckett said: "I do not in fact anticipate any commercial cultivation of GM maize before spring 2005 at the earliest."

The minister also recognised the worries of organic farmers who fear their crops will be damaged by GM contamination. She added: "I am also consulting stakeholders on options for providing compensation to non-GM farmers who suffer financial loss through no fault of their own.

"But I must make clear that any such compensation scheme would need to be funded by the GM sector itself, rather than by government or producers of non-GM crops. The government will also provide guidance to farmers interested in establishing voluntary GM-free zones in their areas, consistent with EU legislation.”

Meanwhile, Scotland's farming union has reiterated that consumer choice will determine whether genetically modified crops are grown in Scotland.

NFU Scotland president John Kinnaird believes if there are no customers for the product then it will simply not be grown.

Kinnaird said: "There will be a great deal of emotional rhetoric surrounding the decision by the UK administration to approve this variety of maize. But it should not be forgotten that the consumer is king and that farming businesses respond to market signals. Ultimately it will be consumers who determine how much, if any, GM material is grown in Scotland.

"NFU Scotland will work with the Scottish executive on the forthcoming consultation on issues arising from GM and non-GM crops being grown in the same area. This will be undertaken before there is any commercial planting of GM crops."