Last week, environmental activists with the backing of global campaign organisation Greenpeace protested against trials of genetically modified crops planned by the University of Zurich, Switzerland.

The open-air GM wheat is set to begin next year. Following previous disruptions at trial sites in Switzerland, the scientists involved have expressed a desire to use a high-security site for their trial.

Opponents of the trial said the effects of GM crops on human health and the environment are not yet fully understood, arguing that the trial represents an unacceptable risk. They also said it would go against laws which forbid farmers from growing GM crops.

The controversial crops are subject to a moratorium in Switzerland (which is not part of the EU) until 2017. Open-air GM wheat trials conducted by Rothamsted Research Institute in Hertfordshire last year sparked a national debate on the issue of GM in the UK.