But Agriculture Minister Jeff Rooker insisted that there was no risk of the resistant strain of maize genes being passed on through animal feed to meat, milk and eggs.

He also denied newspaper reports that resistance to antibiotics could be passed on to bacteria in human stomachs, making people more vulnerable to meningitis and other diseases.

Appearing before the Commons Science and Technology Select Committee, Mr Rooker also admitted that GM food was "unnecessary". But he said the government's role was not to ban it but to make sure it was safe.

There are fears that bees cross-pollinate GM plants with others

Meanwhile, Environment Minister Michael Meacher, also giving evidence to the committee, revealed he was considering raising the distances imposed between GM crop trials and normal plants, amid fears that bees and the wind could spread the seeds to other crops.

The Ministry of Agriculture, in evidence submitted to the committee, said its advisory committee on GM food warned that GM antibiotic-resistant maize should not be used in an unprocessed form in animal feed, in case the resistance was passed on to humans.

Ministers accepted the advice and argued for a ban in Brussels - but although three European Commission safety committees accepted there was a risk, they "considered that this was not significant enough to warrant the material being banned from use in animal feed".

That led to the EC giving the go-ahead to using the resistant crop in the feed, despite UK protests.

But Mr Rooker played down the risks, saying the resistant crops were only used in unprocessed form, and "I have never seen unprocessed maize being used".

He denied that the antibiotic-resistant maize could end up making people vulnerable to meningitis and other diseases.

'No need' for GM foods

The agriculture minister conceded to committee members that there was no real need for the controversial "Frankenstein foods".

Michael Meacher is considering whether to tighten regulations

"Are genetically modified foods necessary?" he said. "When I'm asked that I say no - but the government's role is not to stop them, it's to regulate them."

He "respected" the view of people who wanted nothing to do with GM foods, but his ministry's role was not to promote or discourage particular types of food as long as they were safe.