Thalidomide UK called for more testing of GM foods to find out what effect they might have on health.

"How can people trust the government and the experts after the Thalidomide tragedy?" said the charity's chairman Freddie Astbury.

The Thalidomide drug was blamed for birth defects in more than 12,000 babies after it was prescribed to expectant mothers for morning sickness and as a sedative throughout the 1950s and 1960s.

GM crops: Facing protests

Mr Astbury likened the episode to the current concern over GM foods, saying scientists first warned of the Thalidomide dangers in 1959 after tests on rats showed signs of the possible effects of the drug.

"The government should take Dr Arpad Pusztai, whose research first ignited public health fears, more seriously," he said.

Mr Astbury said the government was ignoring signs that GM foods could prove to be one of the most dangerous chemicals of all time.

"We try to teach people about the dangers of drugs, yet we eat food with chemicals in which we don't fully understand."

The government's advisory body on conservation, English Nature, wants for a three-year ban on some GM foods.

But a report by the Nuffield Council on Bioethics says there is a moral obligation to produce GM crops as they could help feed developing nations.

Organic protest

Meanwhile demonstrators at a genetic crop test site in Hertfordshire have been planting organic crops in place of genetically engineered oilseed rape.

The 40 protesters planted marigolds, onions, cabbage and nettles over a hectare of land at Farnham Hall Farm, Bishop's Stortford, which had been cleared of the GM crop two weeks ago by activists.