Concerns expressed by critics of genetically modified (GM) crops will be taken into account before any decision is taken on whether to permit commercial cultivation, environment minister Michael Meacher said today.

In the strongest signal yet that the Government may be shying away from approving the controversial technology, Mr Meacher revealed that he had asked for an independent expert body to launch a "public debate" on GM agriculture.

He acknowledged that there was widespread public concern about GM technology, and said: "Government needs to listen."

Meanwhile, the chairman of the Agriculture and Environment Biotechnology Commission (AEBC) warned that the farm-scale trials of GM crops currently being carried out will not settle the issue of their acceptability. The Government has previously insisted that it would base its decision on whether to licence GM cultivation on the scientific evidence emerging from the trials.

But AEBC chairman Professor Malcolm Grant said the science was only one part of the question, and that public opinion and EU consent would also have to be taken into account.

He told BBC Radio 4's Today programme: "We produced a report to the Government in September last year ... We tried to explain why we felt the results of the farm-scale evaluations were only going to be a small part of the decision-making process, and not the final piece of the jigsaw.

"It is on our recommendations that the Government is now contemplating a public debate."

Mr Meacher told Today: "There's always been two aspects to the GM trials: First of all, the science which is very important - is there or is there not damage to the environment or to wildlife as a result of GM crops and the herbicide or weedkiller management involved? That is an issue and we should get the results of that next year.

"Secondly, there is the issue of public acceptance. I have always passionately believed in the need for a measure of public acceptance.

"This isn't an easy issue. On one hand you have got farmers who do have the right to cultivate what they like, so long as it is not a danger to public health or the environment.

"But on the other hand, people in a democratic society do have the right to express their views, to have their questions answered and their fears and anxieties taken into account by the authorities.

"It is to reconcile these conflicting interests in a polarised public debate that we are now looking to the AEBC to help organise a more profound and thorough public debate than we have had in this country."

Mr Meacher said that the conduct of the debate would have to be independent of Government. He admitted: "Let's be absolutely honest, Government does not have high credibility. Ministers and officials, however hard we try, however much honesty and integrity we have, we are not believed.

"It should be independent of Government. That is the right way to do it." It had not yet been decided whether the debate should be over whether or not GM cultivation should be allowed or over the extent of regulation to which it should be subjected, he said.

But Prof Grant said: "My view is that we need to have a public debate and the debate should be quite independent of Government.

"If it is to have any credibility and to produce for Government some reliable advice, it has got to be right across all the options. You can't have a fettered public debate."

Mr Meacher said that the issue of what level of GM content is acceptable in products marked "GM free" should also be aired. At present, the maximum permitted contamination level is 1%.