Some background: BASF have been given a licence to trial GM potatoes on two sites: one in Yorkshire, and one in Histon, just north of Cambridge. A third trial in the Midlands had to be cancelled when the farmer involved withdrew his cooperation. The trials in Histon will be carried out by NIAB. The licence took effect on the 31st of March. As yet, no precise location has been specified, but under the terms of the licence, the company has to give notice of the exact location a week before the spuds are put into the ground.

After failing to get trials off the ground in The Netherlands, where Greenpeace successfully overturned three licences that had already been granted by the Ministry of Agriculture, as well as Ireland, where the company failed to make its case, these local trials will be the first to take place in Britain for over three years.

Clare Oxborrow from Friends of the Earth told the audience, a mixture of young and old, how after thirty years of modern GM technology, the biotech industry has largely failed to live up to its promises of more abundant and cheaper food production. In fact, the only tangible outcomes of genetically modified plants have been increased herbicide tolerance and resistance to insects, advantages that only come to play when plants are grown as monocultures on an industrial scale. Presently, only three countries grown GM crops on this large scale: the US, Canada, and Argentina. The main crops are soya, maize, cotton and oilseed rape, most of which go to raise intensively farmed cattle in the developed world. The biggest provider of GM technology is Monsanto, who can lay claim to around 90 percent of GM plant varieties. BASF is among a small cohort of other significant players. These companies have made claims about the benefits of using GM seeds, but these do not stand up to scrutiny. While they say that GM varieties lead to a reduction in pesticides and herbicides, the use of these has actually increased. And the promised increases in yield have not materialized either: yields are similar at best, and in many cases lower than with non-GM varieties. For instance, in Brazil there have recently been crop failures due to drought intolerance of GM crops.

Then there is the issue of cross-contamination, a problem that was cynically exploited by Monsanto when they sued US farmers whose non- GM crops had been contaminated. Closer to home there was the incident of rice imported from the US that was found to contain GM strains that had not been approved for human consumption. By 2006, there had been 132 confirmed cases of such incidents. These can lead to human health problems, such as food allergies and the building up of resistance to antibiotics by gut bacteria.

Next to take to the stage was Michael Antoniou, a molecular geneticist who uses GM technologies in medical research. He agreed with Clare that GM crops have failed to deliver on every single promise since 1994. And there is a good scientific explanation for this. It is not that GM technology itself is a bad thing. After all, Michael uses it every day for his own research. Rather, there are responsible and irresponsible applications of GM techniques. The problem is that GM is a crude method - it is imprecise and the outcomes are unpredictable, both with regard to implications for (human and animal) health and the environment. Agricultural biologists know this: to create reproducible bio-organisms is irresponsible, as the GM changes will spread into the wild. It is even more inexcusable because alternatives exist. When GM technology is used in the lab for medicinal research the safeguard is that the cell will not be able to reproduce, as this is simply too dangerous, as there is no way to control the spread of genetically engineered traits. The crux of the issue is that the GM transformation process is inherently mutagenic: it disrupts an organism's DNA as a side-effect of the introduction of the desirable gene.

This introduction is achieved by one of two methods: through bacteria or through a so-called gene gun, that deliver the genetic material into the cell's nucleus. By either method, this is an inefficient process: with most of the cells treated in this manner, the introduction is a failure, and the cells have to be destroyed. This is because the new genetic material is spliced into the host cell's DNA at a random site. The introduction of the new genetic material interferes with the adjacent DNA, which alters some of the cell's genes, or some of the existing DNA is simply lost. This is one source of undesired mutations.

An even bigger source of mutations, and one whose mechanism is a complete mystery, arrives from the need to grow the cells in laboratory dishes. This causes hundreds or even thousands more mutations to the cell's genetic material. All of this often has no consequences at all, but sometimes the plant's function is impaired. The Food Standards Agency commissioned research (a so-called profiling study), which found that when comparing genetically modified to non-GM plants (including potatoes), there were many disruptions to the plant's normal functioning: some of the plant's characteristics were reduced, some enhanced.

These disruptions work through altering the plant's proteins: this has unknown consequences for the health of the plant itself, and, when consumed, for humans and other animals. There are many examples of GM crop failures in the field. In GM cotton, the cotton balls fell off the plant before they were fully developed. In soy beans, it was found there was a five to ten percent lower yield compared to non-GM soya. In some plants, the stems split. All of these effect can only be caused by multiple gene malfunctions, a sign of the many mutations caused by GM methods.

Even where the effects are not disastrous, they can be undesired. For instance, in rape seed oil it was found that the levels of vitamin E had dropped as a side-effect of increasing the levels of beta carotene. More worryingly, in animal studies it was found that feeding rats GM peas for even a short time led to allergies and other toxic effects. GM potatoes led to gut lesions in mice. Others led to lowered immune systems, effects on red blood cells, kidney failures, or changed blood sugar levels. Even when animal test don't show any ill effect, this does not necessarily mean that the foods are safe for human consumption. In the UK, some GM maize meant for animal feed found its way into the human food chain and caused allergic reactions. GM potatoes pose a particular risk, in that the plants can propagate through their tubers, so no cross-pollination is required for the plants to spread (it is virtually impossible to remove all tubers from the ground). And of course, unlike natural plants, where negative mutations are removed in time, with GM plants the genetic information is fixed for eternity, together with all the known and unknown health consequences.

There are alternative uses of GM technology, however. Desired traits can be introduced to a plant through natural cross-breeding. GM screening is then used to select those specimens where the trait has taken hold. This is a much more powerful, if slightly slower, process compared to the 'shot-gun' approach: much more complex traits can be introduced, with no ill effects, no mutations on the plant’s DNA. Hungarian scientists have used this method to create naturally blight resistant potatoes, so there really is no need for the current trials.

Helen, from GM Freeze, filled the meeting in on the way the trials will be carried out. They will run from 2007 through to 2011, from April to October. Each one hectare plot at NIAB will contain 45,000 non-GM plants, as well as 500 GM ones. There will be a clearance area around the site of 20 metres. The plants will be inoculated with blight, and the impact of this will be compared between the GM and non-GM plants. Up to 334 different varieties of GM potatoes will be tested. In addition to the trial in Cambridge, BASF wants to hold a trial in Yorkshire, the licence for which is currently in consultation.

The stated purpose of these trials is an improved understanding of blight, and the company has said that no animal trials are scheduled. This indicates that these are preliminary tests, and should therefore be conducted in a greenhouse, and not in the open air, especially as the potatoes will be allowed to flower, within 500 metres of allotment gardens, so cross-pollination is likely. Since BASF has not commissioned this (read: provided funds), there won't be any testing for cross-pollination; similarly, NIAB will not study the impact of the GM potatoes on the soil and its micro-organisms.

A bigger question is: why are these trials undertaken? There is no consumer demand for GM foods. There are alternatives: some of the Hungarian blight resistant potatoes have been specifically developed for the UK market. Any way, blight is a disease that is constantly changing, so by the time the GM potatoes would be ready for production, they might be resistant to strains of blight that no longer exist. Of course, there are natural ways of preventing blight. Monocultures are especially vulnerable, so this is all about economies of scale. Instead, organic farmers take care to maintain the health of their soil, and they introduce natural predators, use different varieties, and intersperse the potatoes with different plants to form natural barriers.

Clare confirmed some of these points. She also highlighted that Defra (the department responsible for agriculture) imposed conditions on the trials that are much weaker than those demanded by the Irish government. The Irish asked for independent monitors and a larger separation zone. A similar application was successfully appealed in The Netherlands. What's more, the UK application was personally approved by David Milliband.

The benefits claimed by BASF for the trials have been grossly overstated. BASF has pointed to potential savings in fungicides to fight blight, claiming annual costs of £ 50M. However, the British Potato Council states that the real figure is only £ 3M. Another question is: where is the market for these potatoes? In Europe, 58 percent of people are opposed to GM foods. The supermarkets and McCain, the UK's largest buyer of potatoes, all oppose the trials. McCain said they were "disappointed with the decision" to grant the licence. They have urged the need for consumer consent before any trials are allowed to go ahead.

The meeting was concluded with a question and answer session. Asked what people can do to stop the trials, the answer was that they should write to NIAB with their objections. Asked about the scientific advice given to the government, Michael revealed that in his opinion agricultural biologist are ten years behind medical researchers, having such a poor understanding of the basic biology that they could benefit from taking a few of his undergraduate courses. Some of this seems due to the remorseless drive to commercialize genetic techniques, which has led to a dearth of basic research. Claire agreed with this: the science is mixed up with politics and economics. Helena confirms that government-sponsored research grants have dried up, so that researchers have had to turn to private funding, which has been ever more readily available.

Where do we go from here? Several protests have been planned:

On Saturday 14 April, a walk has been organized along the public footpaths between Histon and Girton, which adjoin the NIAB fields where the trials might take place. Meet at Histon Baptish Church at 11 AM. The church is on the old main road through the village, Station Road (which continues from Histon Road and Cambridge Road). Citi bus 7 takes you straight there.

For more information, watch this space, or contact Cambridge GM Concern: gmfreecambridge@lists.riseup.net

For NIAB contact details, see: http://www.niab.com/contact.html