Monsanto Co. officials say the biotech giant?s enforcement policies against farmers who illegally or unknowingly use the company?s genetically modified seeds won?t change in the wake of a Canadian Supreme Court ruling in favor of Monsanto and against farmer Percy Schmeiser.

But the Seattle-based Campaign to Label Genetically Engineered Foods says the Canadian decision—the first time a high court in any country has ruled how extensively a company can control use of its GM seeds—will galvanize opposition, resulting in more American and international support for legislation against GM foods.

In a 5-4 decision, the Canadian Supreme Court ruled May 21 that Schmeiser violated Monsanto's patent when he harvested and sold GM canola grown on his 1,030-acre Saskatchewan farm. The decision capped a 7-year battle between Monsanto and Schmeiser, who says he shouldn't have to pay for Monsanto GM canola seeds that drifted onto his fields from neighboring farms or spilled from passing trucks.

The court ruled that Schmeiser knowingly replanted and harvested the seeds, but that he doesn't have to pay about $150,000 in court costs because his profits weren't affected by the GM seeds. And, in a decision that causes consternation among anti-GM activists, the court ruled that Monsanto's gene patent also includes plants grown from its GM seeds.

"Monsanto has won an inflatable patent. They can now say that their rights extend to anything its genes get into, whether plant, animal or human," said Pat Mooney, executive director of the Winnipeg, Canada-based ETC Group, an international ecological diversity society.

However, Schmeiser believes that because the court determined that Monsanto is responsible for plants grown from its GM seeds, farmers whose fields are contaminated by GM crops will now be able to sue Monsanto for liability.

A Monsanto spokeswoman says since 1997, the company has settled about 200 patent-infringement cases in the United States without litigation. During that time period, Monsanto sued fewer than 100 U.S. growers. A Monsanto Canada spokeswoman says her company settles out of court 99.9 percent of its eight to 10 yearly licensing disputes with farmers.