The European Commission is split over a plan - strongly opposed by the biotech industry - to scrap the 0.5% GM threshold for sugar beet, fodder beet, potato and cotton seeds and introduce a 0.3% threshold on maize and oilseed rape.

Also causing dissent in Brussels is a proposal to include 17 genetically modified varieties on the EU's approved seed catalogue.

Reflecting intense lobbying from both industry and the environmental movement, Commissioners have been unable to agree either the thresholds or the catalogue plans. A decision is due on Wednesday 8 September but may have to be postponed.