Officials will begin a new study to decide if the trials should be delayed or even abandoned after the cabinet backed down from relaxing three-year-old regulations governing the crops.

Fierce criticism of the trials has been led by environmental group Greenpeace which said the government had rushed into a decision that threatened the health of the Thai people.

The government said public opposition had contributed to its decision and accepted that genetically modified organisms (GMOs) remained a debatable issue across the world.

"The Prime Minister said there should be a study about GMO because if the government rushes to make a decision, it may lead people to think the government supports GMOs," government spokesman Jakrapob Penkair told AFP. "We will do the study on paper, not by testing."

Greenpeace said Wednesday that the government was still determined to push ahead with allowing GMO crops in Thailand.

It claims that a planned government campaign aimed at "improving public understanding" would be used to persuade a sceptical public to embrace the idea of GMOs.

Prime Minister Thaksin Shinawatra has been accused of bowing to pressure from US corporate giants like Monsanto, which is pushing to test GM corn strains, to reverse a ban on trials.

Opponents said the US government had insisted that Thailand grant intellectual property protection for GMOs before they reach an agreement on free trade.

Thaksin Wednesday dismissed suggestions that his earlier backing for open-field trials was linked to US pressure.

But he remained bullish over the prospects for GM crops in Thailand. "The concern over GMO testing outside the lab being dangerous for other products is an overreaction," he told reporters. "Thais have limited information about GMO testing.

"The study will be carry on until we can find a compromise."

The cabinet in 2001 banned GMO field trials. Current law forbids the public sale of GMO seeds and requires products containing more than five percent of a genetically modified ingredient to be clearly labelled.

Controlled experiments are allowed but Greenpeace claimed government trials of GM papaya contaminated a non-GM farmer's field 60 kilometres (37 miles) from the site.

Varoonvarn Svangsopakul, from Greenpeace Southeast Asia, said the climbdown was only a "partial victory" for opponents of GMOs.

"It's not over yet. The government agencies who support GMOs will try hard to put it back on the agenda," he said.

"I think the government is just buying time. They will launch a series of advertisements until the people accept the idea."

The United States is the world's biggest GMO producer but has struggled to persuade other nations to accept the products.

However in Asia, the Philippines and China already have huge plantations producing GM crops such as corn and cotton.

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