Shadow Trade and Industry Secretary John Redwood said his party had no confidence in the cabinet office minister.

Cunningham: " We will have clear labelling to ensure consumers have proper information"

Dr Cunningham has repeatedly dismissed calls for a moratorium.

He said GM foods on sale in Britain are safe and that there was no medical evidence to suggest they should not be allowed into the food chain.

He told BBC's Radio 5 Live that clear labelling on food products would be available to allow people to chose whether they ate GM Food.

"The government is pressing ahead to ensure consumers do have proper information," he said.

But he did agree that "caution and vigilance" were needed, and admitted it carried "some potential risks" and caused unease.

Shadow Agriculture Minister Tim Yeo said the Tories accepted that field trials of GM crops had to continue to assess their safety.

But he said said there were "quite substantial dangers associated with the large-scale commercial growing of GM crops".

He also suggested the government was "very, very close to a number of the companies that are involved".

He told the BBC's On the Record this was the "only possible explanation" for its "apparent willingness" to allow the commercial growing of such foods.

'Danger of commercial pressure'

"We now have information that Monsanto has hired people who were working very closely with Labour both before and during the last election," he said.

"There's a danger that commercial pressures on the government are going to influence the decision rather than the overriding need, which is to protect the consumer."

This is the latest development in the growing row over GM food. A research laboratory, which forced one of its scientists to retire after he claimed there were potential risks from GM crops, is at the centre of a new dispute.

Environment Correspondent Robert Piggott: "Huge profit potential"

The government-backed Rowett Research Institute received £140,000 from Monsanto, one of the leading companies in the GM food industry, according to the Mail on Sunday newspaper.

The report alleges Monsanto gave the money for research into animal feed.

Rowett Institute scientist Dr Arpad Pusztai was sacked after saying his experiments showed the brains and immune systems of rats were damaged by eating GM potatoes.

But earlier this week 20 scientists re-examined his work, concluding his findings were justified.

Dr Cunningham dismissed reports that there were risks involved with GM potatoes as "ridiculous".

He told GMTV's Sunday Programme: "Because there's been some dispute about some genetically-modified potato experiments in the laboratory, that is no reason to suggest that we should bring the whole of our bioscience and GM technology and research grinding to a halt.

Walker: "The reality is that all of us are taking part in an experiment"

But action against GM Foods has already been taken by supermarket chain Iceland, which has banned them. It claims they are harmful to the environment.

"I think it's the biggest and most dangerous experiment in the whole of human history," Iceland's chief executive Malcolm Walker told BBC Radio 5 Live.

He said his concern for the consumer was about choice. He said GM Foods, "which can already be found in 70% of processed food", were being added "surreptitiously" by biotech companies.

International pressure

The row comes as an international conference in Colombia tries to reach agreement on the international trade of GM crops.

US plans to dilute trade protocols

Developing countries want western companies to be held liable if their genetically-altered products harm the environment.

But the US, which has some of the biggest biotechnology companies, wants to dilute the proposals so there can be as free a trade as possible.

The European Union is urging caution. It argues trade should only be liberalised once is it certain the products cannot do any harm.