Members of the 13-member Advisory Committee on Releases to the Environment (Acre) have written to Mr Meacher to protest that his plan, leaked last week, will weaken their combined experience and expertise. It comes, they argue, just as growing concern over GM crops and food means that both are more important than ever.
Dr Julian Kinderlerer, of the University of Sheffield's biology and biotechnology department, who has been on Acre since its inception in 1992, told The Independent: "Some of us hit the roof when we were told about it last week.
"I have written to Mr Meacher to say that there is a difference between expertise and experience, and we need to have both represented on the committee.
"It is all very well knowing the theoretical analysis of a crop's risks. But you need someone who can point out that it will be farmed by two men pushing a wheelbarrow, neither of whom cares about genetic release."
Professor Alan Gray, another Acre member, said: "The point is that it is a committee which deals with science. There may be a bias of people from industry - but would you prefer to fly in an aeroplane designed by people with degrees in ethics, or aerospace design?"
Acre is crucial in deciding what GM crops are approved for trials in Britain, and how widely they might be introduced.
But its critics contend that it has never turned down any application for GM crop trials, and has refused to consider suggestions by English Nature, the official conservation advisers to the Government, for a moratorium on the commercial growing of GM crops.