The group is demanding genetically modified wheat trials be stopped, claiming GM foods are unsafe and the wheat industry is being taken over by pro-GM interests.

Genetically modified wheat is not currently grown for human consumption in Australia, but GM cotton and canola is.

The Office of the Gene Technology Regulator has approved field trials of 1300 modified wheat and barley lines this year, up from 150 trials in 2004.

Coupled with investments in Australian wheat by the modified-seed multinationals Monsanto, BASF and Agrium, Greenpeace fears Australia's opportunity to be a leading producer of unmodified wheat is under threat.

''There's no way of knowing the impacts of GM [genetically modified] wheat,'' said Claire Parfitt, who wrote the report.

Food with genetically modified ingredients must be labelled, but not the products of animals fed genetically modified feed.

Greenpeace is campaigning for Australia's bread and cereal manufacturers to rule out using modified wheat, after more than 160 top signed its GM-free chefs' charter.