Oxfordshire's genetically modified food protesters have stepped up their campaign to rid the county of test sites after Tony Blair's admission at the weekend that they may damage human health and the environment, writes Amanda Castleman.

"The Prime Minister's comments are incredibly welcome," says Ray Foulk of the GMO campaign in Oxford. "But it's not far enough. The notion to carry on crop trials is bad news. This is still a source of danger."

Three sites in Oxfordshire host GM experiments: Hill Nurseries in Abingdon, University Farm in Oxford and Model Farm near Watlington, one of six farm-scale projects in the country.

In July, hundreds of eco-warriors destroyed the oilseed rape crop in a field at Walington during a Stop The Crop rally. Neighbouring counties - Warwickshire, Northamptonshire, Buckinghamshire and Gloucestershire - are free of test sites, though the councils in each county have no remit to ban testing. If a farmer is offered an attractive enough financial package on his land by researchers, there is nothing to stop testing going ahead.

Indeed, Oxfordshire County Council says it has "no influence whatsoever" on the use of private land, but Green councillors have passed along local concerns to the Government.

Mark Lynas, of Oxford Corporate Watch, agrees that stopping trials is key. He says: "They threaten to spread GM pollen and other contaminants on a vast scale throughout the countryside."

A £4.2m court case is already pending in North America, as farmer Percy Schmeiser argues that Monsanto's GM oilseed rape infiltrated his crops. The company sued him for cultivating their gene, demanding all profits from the crop and damages. The case will go to the Canadian Supreme Court in June.

Meanwhile, closer to home, Tesco has extended its GM ban. Fruit and vegetable suppliers are now forbidden to grow on sites previously used for GM crops. This is to ensure that DNA and toxins do not remain in the soil and change the ecology.

Mr Foulk confirms: "Many farmers are too scared to allow GM crop trials, which have the potential to devalue land, especially if it becomes blighted."

A survey by researcher Mintel shows that GM fears are the top health concern in Britain. It revealed that 47 per cent of British people worry about GM safety - and this number is on the rise. The jury is still out on what GM risks might be, and there is scientific infighting about sickly butterflies and rats. Oxford zoology professor Sir John Krebs landed in the thick of the fray when he became the first chairman of the Food Standards Agency.

He says: "You can not generalise. You can't say GM foods are safe or not. It is clearly something that you have to look at on a case-by-case basis."

He does back more detailed labelling, however, which has angered the food industry. But Sir John believes in the public's right to decide - even if a product contains only traces of GM in an emulsifier or processed oil.

This week he chairs a conference on the subject in Edinburgh where industrialised nations meet to discuss biotechnology regulations.

He told the BBC that learning to live with GM foods safely is the next step because "the genie is out of the bottle. We can't turn back the clock". Another Oxford professor, Alan Ryan of New College, entered the debate by chairing the Nuffield Council on Bioethics last year.

He says: "GM crops can bring together new gene combinations not found in Nature. This has caused unease about effects on health over the long term.

"Attention has also focused on the possible risk of increasing human resistance to antibiotics through the food chain."

These concerns - and others about environmental damage - led to a ban on commercial planting of GM crops until 2003. However, protesters would like to see a longer ban and more laboratory research. Many, like Mr Foulk, want a moratorium on GM animal feed as well.

"The Government's policy on GM is all about consumer choice. But all meat, eggs, milk, butter and cheese come from animals reared on GM soya or maize. Where's the choice there? "There's not even labelling. Unless you're vegan or 100 per cent organic, you can't avoid GM. Who knows what it's doing to the animals or to ourselves?

"Genetic engineering is hit or miss, the process is fairly crude," Mr Foulk points out. "The science is so new and so limited. It's very dangerous. Genes cannot be recalled if they go wrong.

"We need to ask ourselves if science can control this?"

*Contact the GMO campaign via its website, www.millennium-debate.org

The Government's information site is www.gm-info.gov.uk

Story date: Tuesday 29 February

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.