Britain today hosts a weighty international conference in Norwich at which leaders of industry and agriculture will examine how biotechnology can tackle global hunger.

Inevitably, there will be claims that genetically modified 'golden rice' will lead the way in saving large numbers of lives and prevent child blindness among those struggling to live on diets lacking vitamin A nutrients. What the conference will lack are representatives from the millions of poor people in developing countries. The very people at whom golden rice will be targeted have received no invitation to take part in its progress.

Yet there remain serious doubts among nutritionists about its effectiveness and they insist that backing for sustainable, cheaper systems could bring a substantial reduction in vitamin A deficiency. Alternative, more sustainable ways to farm and give the poor extra vitamin A will be presented at a rival debate in Norwich.

This conference's speakers include an Indian farmer who served on the first of a series of court-style citizens' juries' facilitated by ActionAid. The farmers' jury heard evidence for and against GM foods from witnesses including Monsanto and returned a verdict against planting GM seeds without legal safeguards and more research lasting up to a decade.

Last week Monsanto declined to participate in the second of the trials before a jury of small-scale farmers and poor urban consumers in northern Brazil. A former judge presided over the two-day hearing at Fortaleza, the event taking place as Brazil decides whether to remain the world's only major farming export country to ban GM crops.

Monsanto's GM soya beans had been outlawed in Brazil, but the company and government ministers are now contesting that decision. It will also be easier to approve GM products with new laws. Subsistence farmers who cannot afford GM seeds worry that if the ban is lifted, bigger producers would outstrip them and they would be forced to rely even more on the few giant seed firms.

This, they say, could imperil traditions for harvesting practices, saving and exchanging seeds and making technological choices, which have all been passed on through generations. In addition, poor farmers fear complex and patented technology will raise food prices and hit the poor hardest. In the trial, eminent pro-GM advocates had a groundbreaking direct opportunity to convince poor citizens that their technology can overcome food shortages and the arid regional climate.

After more than 14 hours of considering evidence from both champions and sceptics, the jury returned a forceful GM thumbs down. The jury reached unanimous conclusions that genetically modified organisms do not help unearth a solution to feed the hungry, nor provide access to food and food security for the poor and meet the interests of small-scale farmers. There is inadequate proof to justify releasing GMOs without damaging people's health. Nor, they decided, was there enough available information for consumers and farmers to exercise their right to choose. The jury urged that people should have the chance to be better informed and consulted on a wider basis, with state incentives for small-scale farming.

Their conclusions will send a timely signal to politicians and big business across Brazil and around the globe - in particular within another developing country, Thailand. The Thai government has been leading the way in Asia recently with its decision to stop current field trials of GM crops. The agriculture ministry was ordered to withdraw approval for the trials to protect farmers, biodiversity and the environment from genetic pollution. The Bangkok administration had already banned all commercial growing of GM crops. This new ruling should halt Monsanto's trials of two GM crops in Thailand - corn and cotton. It will further strengthen the British campaign for a five-year GM freeze.

The campaign boasts a wide coalition spanning local authorities and community and national voluntary groups, embracing the National Federation of Women's Institutes.

However, despite the drive for a freeze, the British government is keeping its head down in the debate on whether GM crops can feed the Third World. But at the same time it is charging ahead with the next round of UK GM field trials. Farming is a lifeline for three in four people in poor countries. Basic research, which assesses the effects of GM crops on their societies, economies and habitats, is an essential first step. And we should not forget that poor farmers need fair agricultural trade, rather than a free for all, with access to rich countriesi markets and safeguards against cheap dumped produce.

The great and the good who assemble for the conference at the government- funded John Innes research centre will need to demonstrate more 20:20 vision than just talking among themselves. Global power brokers in particular must heed the voices of the poor, not impose unilateral prescriptions under the guise of huamnitarian aid or succour. Otherwise, the way forward will be paved with good intentions, but may end in a road to market ruin for poor farmers everywhere.

Koy Thomson is policy director of ActionAid