But Tony Blair insisted during question time that the Government would proceed logically and scientifically and "not on the basis simply of prejudice of either side of the debate, because that would only serve to increase public concern on the matter".
Mr Hague said: "The effect of the muddle in government policy is to increase public concern and not to decrease public concern. Why doesn't the Government do the common- sense thing and listen to the advice of its own experts and at least put on hold the release of these new and unfamiliar seeds until the research is done?
"When those concerns exist on that scale, wouldn't it be better to impose a moratorium and to do so now?" he said.
Replying, Mr Blair insisted: "We are doing research on this and of course there is a government committee looking at it too. But I think we do have to proceed on the best scientific evidence, since we are also talking about something where the potentials are very great indeed ... the worst way to proceed is to raise fears in the public mind before evidence is put before them."
Mr Hague also pointed to the "huge public concern" about the possible health and environmental impact of GM foods after reports suggested supermarket loyalty cards would be used to monitor their purchases and compare them with cancer cases.
Earlier Tim Yeo, the shadow Minister of Agriculture, referring to the reports, claimed the Government was using the public as "unknowing guinea pigs" in a "vast but secret human experiment" on genetically modified foods.
His concerns were echoed by Labour MPs who called for an immediate ban on the commercial use of GM products, so-called Frankenstein foods.
Joan Walley, the MP for Stoke North, claimed it had caused an outbreak of a fatal disease that infected 5,000 people, disabling 1,500 and leaving 37 dead.
She told MPs that a mix-up of soya beans with a batch of food supplement produced by genetically engineered bacteria had led to the epidemic in the United States.
"After GM soya beans were mixed up with non-GM soya beans in America, and Monsanto (the biotechnology company) has apparently persisted in their view that segregation is impracticable, it has become impossible for the consumers of many processed foods to know whether or not those foods contain GM soya.
"Some 60 per cent of processed food uses soya. The vast majority of us therefore have already been exposed to these beans, whether we like it or not."