US President George W. Bush launched a legal challenge at the WTO on Tuesday, in an attempt to force Europe to accept imports of American genetically modified crops.
Raising fears of a full-scale transatlantic trade war, Washington described Europe's five-year-old ban on GM imports as unscientific and a violation of WTO rules.
"People around the world have been eating biotech food for years," said Robert Zoellick, America's leading trade negotiator. "Biotech food helps nourish the world's hungry population."
Two weeks ago Brussels upped the stakes in the looming trade war in a separate transatlantic dispute over tax breaks for some of America's largest exporters.
Europe's chief trade negotiator, Pascal Lamy, has given Washington until September to change its laws or face a US$4 billion sanctions bill authorized by the WTO.
EU officials described yesterday's challenge as "legally unwarranted, economically unfounded and politically unhelpful," and accused the US of bringing the case against Europe to put pressure on other countries which are also introducing curbs on GM imports.
"The European commission finds it unacceptable that such legitimate concerns are used by the US against the EU policy on [GM food]," officials said.
More than 70 percent of US soybeans and one-third of the American corn crop come from biotech seeds. European officials deny that there is a moratorium on GM imports, but several member states led by France have blocked all applications since 1998.
The case is likely to inflame opinion among environmental lobbyists and anti-globalization protesters ahead of a meeting of trade ministers in Cancun, Mexico, in September.
Greens accused the US of bowing to pressure from its powerful biotech lobby.
"By trying to use the WTO to force GM foods on European consumers, the US is launching the mother of all trade wars and could bring about the institution's collapse," said Caroline Lucas, a Green party Member of European Parliament.
Under WTO rules, member states are allowed to block imports if they can prove there is a danger to public health or the environment.
Despite pressure from hostile voters, member states are determined to keep the ban, even though studies have so far failed to uncover any dangerous side-effects.
"We've waited patiently for five years for the EU to follow the WTO rules and the recommendations of the European commission, so as to respect safety findings based on careful science," Zoellick said.
Washington claims the ban has cost its farmers hundreds of millions of dollars in lost sales.
But European consumers are likely to prove resistant even if the restrictions were lifted, as there is widespread animosity toward genetically modified food throughout Europe.