Environmental groups have criticised a decision by Thailand's government to end the country's 2001 ban on field trials of genetically modified organisms (GMOs).

The Thai Prime Minister, Thaksin Shinawatra, denied the decision had been influenced by pressure from the US.

"The cancellation of the GMO ban was not because of any US senator lobbying. Nobody can lobby me, only the Ministry of Science and Technology lobbied with information," Thaksin was quoted by Agence France-Presse as saying.

Environmental group Greenpeace said the Thai government had made a "rushed" and "reckless" decision.

"The decision made by a small group of bio-technology advocates will benefit only a small group of companies, and ignore the rights of farmers and consumers of the nation. It is apparent that the decision was based on false claims and assumptions, which will lead this country into disaster," said Jiragorn Gajaseni, executive director of Greenpeace Southeast Asia.