English Nature Chair Baroness Young: Worried about long-term effects

English Nature wants more research into their effects on wildlife.

Groups including Friends of the Earth and the Royal Society for the Protection of Birds have welcomed the statement.

The effects on wildlife are unknown

English Nature said releasing the untested crops could spell the end for some birds such as the skylark and corn bunting if it causes the seeds and insects on which they feed to disappear.

It called for a three year moratorium on the commercial growing of these new crops.

Devon trial

The call comes just a week after the government decided to allow trials of genetically modified maize on a Devon farm.

Neighbouring organic farmer Guy Watson, backed by Friends of the Earth and the Soil Association, is going to the High Court on Thursday to challenge this decision.

"Precautionary principle"

Dr Brian Johnson, English Nature's advisor, said that existing research had to be completed before English Nature could have a better idea of the possible effects of genetically modified crops on farmland.

"We must adopt the precautionary principle if we are to maintain England's biodiversity and wealth of wildlife," Dr Johnson said.

There have been more than 20 attacks on sites this year by groups protesting at the introduction of genetically modified crops.