Christian Aid has challenged claims by producers of genetically-modified GM food that they can ease Third World hunger.

Instead, the UK development charity warns that biotechnology companies' efforts to sell GM seeds to Third World farmers may also rob Western consumers of their freedom to choose or refuse GM foods.

In a report called Selling Suicide: Farming, False Promises and Genetic Modification in the Developing World, Christian Aid says GM crops will not help to feed the hungry.

"The false promise of genetic modification is that it will benefit small farmers. The reality is that high-tech farming may make them more vulnerable," it says.

Rising costs

The charity says the increased levels of debt incurred by Indian farmers from using expensive hybrid strains of cotton have already driven hundreds of them to suicide.

The BBC's Robert Pigott: Many farmers will find early profits on GM crops hard to resist

"Christian Aid-supported organisations there fear that GM crops could lead to worse problems as rising costs of seeds and inputs may drive farmers further into debt."

The report says one of the most worrying characteristics of GM seeds is what is known as the "terminator technology", by which seeds produce crops that are themselves infertile.

Market regulation

This means that farmers cannot collect seeds for the following year's crop, although at the moment 80% of crops planted in the developing world are from saved seeds.

Andrew Simms of Christian Aid and Tony Coombes of Monsanto discuss GM crops

The authors say the basic purpose of the terminator technology is to maximise seed company royalties. The technology has been rejected by India.

"But campaigners fear that regulation is inadequate to prevent its infiltration of the market.

"They say that seed-saving is so fundamental to Indian rural society that any threat to the practice is a threat to the society itself."

Issue of control

The report, based on investigations in India, Ethiopia and Brazil, says there are several concerns over GM crops:

• They threaten to damage the livelihoods and the lives of millions of small farmers
• They will put too much control over the world's food into a few hands, since 10 companies control 85% of the global agro-chemical market
• They could end UK consumer choice over GM foods.

Professor Don Grierson: Christian Aid have not found out the positive things about GM crops

The report says one third of UK soya, used in almost all processed foods, comes from Brazil, the world's second largest soya producer.

At the moment Brazil is free of GM crops. But "a concerted drive by all the major biotech companies" may soon change that.

Food shortage

The GM companies themselves argue that their technology is the only realistic solution to the shortfall in food supplies that will "inevitably" arise from world population growth.

The BBC's Margaret Gilmore: GM producers say higher yields will ease world hunger

They argue that "traditional" plant breeding techniques cannot possibly provide the increase in yields that will be necessary to feed everyone.

With up to 40% of the world's food production lost to weed growth, pests and diseases, and with increasing desertification and urbanisation diminishing the amount of available agricultural land, the companies believe the demand for their technology will become irresistible.

Tony Coombes, from the biotech company Monsanto, accused Christian Aid of getting the facts wrong. He says the terminator technology does not, as yet, even exist. Although Monsanto has patents on it, he says such technology is at least five years away from possible commercialisation.

"Nobody is forcing farmers to do anything," he adds. "If they want to carry on saving their seeds and using them in future seasons, then that is fine."

Professor Don Grierson, who has developed GM tomatoes at Nottingham University, says Christian Aid has failed to find out about some of the benefits of the new technology, "such as insect and virus resistance, improved nutrition and reduced post-harvest spoilage.

"There is no spraying involved, the seeds inherit the change and this technology can be given to people in developing countries," he says.