Business consultant Dr Alan Rae, who runs East Sussex organic vegetable nursery Fletching Glasshouses, argued that growing food sustainably and locally is a better way of feeding the world.
"GM doesn't increase yields, nor decrease pesticide use and does produce pesticide-resistant weeds," he said.
East Malling Research chief executive Professor Peter Gregory, argued: "A lot of what has gone on in public domain has been the exploitation of fear. About two trillion meals containing GM products have been eaten in the past 12 years, yet there's not been a single case of ill health reported."
Also speaking for the motion "GM is necessary to provide the human race with food" were chartered surveyors and land agents Kentlands managing director Alasdair Paterson and recruitment body Fresh Start co-ordinator Douglas Jackson.
The audience voted in favour of the motion.