If the not-guilty verdict in the case of 28 Greenpeace campaigners charged with criminally damaging six acres of genetically modified crops is the "green light" for direct action across Britain, then farmers in England, Scotland and Wales taking part in the trials have good reason for concern.
There were cheers from the public gallery at Norfolk Crown Court on Wednesday when Lord Melchett, a former Labour minister and executive director of Greenpeace, and 27 co-defendants were cleared of criminally damaging a GM maize crop in Norfolk last year. The story was splashed across the front pages, reminding the Prime Minister, Mr Blair, that he could not afford to dismiss accusations that he had not listened to public disquiet.
Lord Melchett carefully dodged the question of whether he planned further action by refusing to rule it out, and therein lies the difficulty for the farmers. Faced with a verdict that according to the president of the National Farmers' Union, Mr Ben Gill, gives licence to "wanton vandalism and trespass," GM farmers now fear that "open season" has been declared on their land by environmental campaigners.
At a time when direct action advocated by farmers and truck drivers can bring the country to a standstill, farmers' confidence in GM trials is being tested. Reassurances from the Crown Prosecution Service that it would not rule out further prosecutions and the Department of Environment's insistence that protesters "will not stop the trials going ahead", are unlikely to restore confidence when the courts accept damaging GM crops to prevent GM pollen contaminating non-GM crops.
Even before the Norfolk trial, however, some farmers bowed to local criticism and pulled out of the voluntary three-year trials. There are 73 sites around Britain taking part in the scheme, but none in Northern Ireland, and it is hard to imagine there will be many more volunteers when farmers feel exposed to the threat of direct action without the protection of the courts.
If environmental campaigners or indeed anyone attracted by direct action draw inspiration from the success of Lord Melchett and his supporters, the Greenpeace protest will not be the last of its kind on the issue. It could also encourage similar protests over other issues, using the same legal defence.
On the strength of past experience, Mr Blair will not budge and call off the trials. Whatever the rights and wrongs of GM crops, direct action has seriously undermined farmers' confidence and if that fear takes hold, it could be enough to stop the trials anyway.