Guy Watson believes there's a risk of cross-pollination between the maize and his own crops, which could mean he can no longer call his produce "organic".

Guy Watson: fears his farm will no longer be organic

"One of the very firm rules of organic farming is that no product can contain any genetically modified material whatsoever," he said.

Mr Watson estimates he could lose up to �20,000 as a result and is seeking to have the experiments stopped because he believes trials of the genetically altered crop might breach Government regulations.

But Dr Thomas Jolliffe of seed manufacturers Advanta Holdings UK Ltd says that there is no risk attached to the experiments they are carrying out in Devon.

"There are no risks perceived with this genetically engineered maize," he says.

"While cross pollination is theoretically possible, the consequences have been looked at and are regarded as not being significant."

The case won't be about the rights and wrongs of genetically engineering crops, it will be decided by the technicalities of how the government decided to allow the trials to go ahead.

But with public interest growing in this controversial technology the outcome will be closely watched.