Michael Meacher, the former environment minister, has accused Tony Blair's spin doctors and ministers of systematically ignoring or rubbishing the evidence that genetically modified crops could be a health hazard or could harm the environment.
Mr Meacher's warning is calculated to ignite the public debate on genetic modification as the Government prepares an official report that is expected to clear the way for GM foods to go on sale on supermarket shelves.
During his six years as Minister for the Environment in Tony Blair's government, Mr Meacher was rumoured to be almost a lone voice seeking to delay the commercial cultivation of GM crops until more scientific evidence had been built up about their effects.
Writing in today's Independent on Sunday, in his first published article since being sacked by Mr Blair, Mr Meacher lists a series of reports and findings which suggest that the full impact of GM technology is still dangerously unpredictable. Many of the health tests carried out are "scientifically vacuous", he claims.
In one of the most damning passages, he says: "The only human GM trial, commissioned ironically by the Food Standards Agency, found that genetically modified DNA did in fact transfer to bacteria in the human gut. Previously many scientists had denied that this was possible.
"But instead of this finding being regarded as a serious discovery which should be checked and re-checked, the spin was that this was nothing new and did not involve any health risk."
In a television interview to be broadcast this morning, Mr Meacher suggests that the push to have GM foods on sale in the UK has been backed by "senior people in government who are committed to the biotechnology industry". Though he did not mention names, it is likely that one of the people Mr Meacher had in mind is the Science minister, Lord Sainsbury, whose family owns the supermarket chain.
"There is nothing wrong with biotechnology, in terms of drugs and pharmaceuticals," Mr Meacher tells GMTV's Sunday Programme. "The only issue is our food. There are people who are strongly in favour. Tony Blair, it is said, is one of them, but of course there are others."
When challenged by Mr Meacher over GM foods in the Commons last week, the Prime Minister dropped another strong hint that he is in favour of seeing them on sale in the shops. He said he was "worried by voices here and in the rest of Europe" that did not give what he called "proper consideration" to the potential benefits of GM technology.
Mr Meacher also confirms what most observers had suspected, that he was sacked by Mr Blair, although the official Downing Street announcement said that he had "resigned".
Until last week, Mr Meacher, 63, had served longer as a minister and frontbench opposition spokesman than anyone else in government, having been on the front bench for 27 of the past 29 years since Harold Wilson appointed him a junior industry minister in 1974.
The Government is due to make a decision on GM foods later in the year, after the publication of a report next month by a team headed by the Government's chief scientific adviser, David King. The study is intended to be the most authoritative to date.
GM foods can be bought at supermarkets in the United States and have been consumed by millions of people, none of whom are known to have suffered any harmful effects.
The Paris-based International Council for Science published a study last week which concluded that the GM foods already on sale are harmless, though its report warned that there was uncertainty about more complex products that have not yet reached the market.