All imports of United States corn have been stopped at British ports following the discovery that the US has been illegally exporting a banned GM maize to Europe for the past four years.
The unprecedented move, which has angered the Bush administration, follows efforts to hush up and play down the scandal on both sides of the Atlantic. For weeks the official food watchdog failed to look for imports of the maize, which is banned on health grounds. It has been forced to take action by the European Commission.
The two main opposition parties yesterday blamed the delay on a pro-GM and pro-US bias in the Food Standards Agency, and pledged to correct it if they came to power.
The scandal - the worst yet involving GM imports - centres around maize named Bt 11, modified to repel a pest called the corn borer. It also contains a gene conferring resistance to antibiotics. All such crops are banned in Europe because of fears that the resistance could spread to consumers via the food chain.
Syngenta, the biotech company that developed the maize, told the US government last December that the crop had been grown over 37,000 acres of the country since 2001, because it had been confused with a similar, approved, maize. It was fined $375,000 (£200,000) for the blunder.
But the Bush administration failed for three months to inform European customers that they were importing a banned maize. The scandal was admitted only after it was exposed by the scientific magazine Nature, on 22 March. Even then the US failed to mention that the maize contained the gene for antibiotic resistance.
Europe is estimated to have imported about 1,000 tons of the banned maize, as animal feed. The EC says it cannot eliminate danger to people who consumed meat or dairy products from livestock. It has no idea where in Europe the banned maize has gone or whether the US stopped exporting it.
The Department for Environment, Food and Rural Affairs said only "very small" amounts of maize were involved, echoing a statement from Syngenta, and there was "no actual indication" any had ended up in the UK. The Food Standards Agency refused pleas to try to identify the maize in Britain. Itsimport was stopped on Friday and supplies in transit are being tested at the ports.