The anti-GM food lobby has claimed that senior scientific advisers to the Government have a vested interest in promoting GM issues because of research grants their institutes receive from biotechnology companies.
Although the members of scientific advisory committees have to declare any personal and "non-personal" interests - which covers research funding to their institutes - critics claim that commercial funding leads to unofficial promotion of GM food and crops.
A significant proportion of the Government's food advisers have declared both personal and non-personal interests, which range from paid freelance consultancies to being in an academic department which receives industry funding.
Almost every academic member of the Food Advisory Committee (FAC) and the Advisory Committee on Novel Foods and Processes (ACNFP) has declared non-personal interests, which could appear to conflict with the objectivity of their advice.
However, Sir Colin Campbell, chairman of the FAC, said such interests do not affect the impartial nature of the advice these scientists give. "The accusation that members have commercial ties is a sweeping generalisation," he said.
There is a danger that scientists, who give their advice on an unpaid basis, will step down from government committees because of the nature of the unfair accusations levelled against them, Sir Colin said.
"The accusations are sometimes malign in the way they are phrased. If these scientists are trawled through the press with such accusations, they will leave," he said.
Professor Janet Bainbridge, who chairs the ACNFP, said all links between scientists and industry are open and transparent. Furthermore, if a subject is to be discussed at a committee meeting, anyone with vested interests has to leave the room.
"As the chair of a committee I want the best scientific advisers I can get and, if this criticism goes on, the scientists are going to say `I don't need the hassle'. They are not in it for the money after all," she said.
Over the past 20 years, since Margaret Thatcher, the former prime minister, overhauled science funding, scientists have been encouraged to seek financial support from industry to bolster public research grants. This means that many of the best scientists almost invariably receive commercial grants, said Professor Catherine Geissler, head of health sciences at King's College London and a member of the FAC.
She has declared non-personal interests because members of her university department receive industry support. "There is a great deal of pressure to bring in funding from any source," she said.
Doug Parr, scientific director of Greenpeace, said: "Realistically, the argument saying that you won't find a good scientist without industry connections is almost certainly right. An obsessive focus on industry connections is unhelpful."