The government has launched a review of GM crops with controversy surrounding what issues it won't be looking at.

Chief scientist professor David King will lead an investigation by experts to answer public concerns and assess its impact on the environment.

"It should enable us to take a really comprehensive and open look at the science relevant to GM," King said in an open letter to UK scientists.

But one of the most controversial areas of genetically modified crop trials has been excluded.

The results of the farm-scale field trials experiments will not be published until next summer and as a result will not be included in the review.

King believes that the field trials results will come too late to feed into his review and that they would detract attention away from the rest of his work.

In a briefing to journalists he said: "It is in my view absurd if we were to focus down on one set of trials in the UK, on one aspect of GM crops and that's the herbicide."

"If we wait until the results emerge and then include them in our review, that would be the focus of all your attention and that would be completely wrong because it would be a total imbalance to the scientific input of our review."

But anti-GM campaigner Adrian Bebb said: "I think the government is trying to rush the whole process and is completely out of its depth."

The Friends of the Earth spokesman feels that the "rush" to complete the debate before the crop trial results were published was down to pressure from the bio-tech industries.

"They have only got a voluntary agreement with the biotechnology industries not to plant GM crops - that time is running out," he said.

Professor Howard Dalton, the chief scientific adviser at the Department for the Environment, Food and Rural Affairs (DEFRA), who will sit on the 24 person panel, sought to bridge the two sides.

He said that the field trials were "only a very small part" of the review of GM science, but that the results "might" be fed into the King team's report.

"Whenever we are going to write this report. it might well be the results of the farm-scale evaluations are published by then - we just don't know," he said.

The King review is a response to DEFRA's request for a national public debate to find out whether the UK wants to grow GM crops.

King will launch an online consultation project today to encourage the scientific community to take part in the debate.

A new website, www.gmsciencedebate.org.uk, invites contributions from all interested parties and promises that they will be "the key source" of the review.