Updated

Some Washington state wheat farmers have thrown their support behind legislation requiring labeling of genetically modified foods, giving food safety advocates fresh hope that lawmakers also will get behind the bill.

They haven't been receptive to the idea in the past, and lawmakers at the national level and in more than a dozen states have rejected similar proposals in the past year.

But in an unusual pairing, a handful of Washington wheat farmers have joined so-called "foodies" to back the latest bill, fearing exports will be hurt if and when genetically modified wheat gains federal approval. The U.S. exports half of its wheat, and in Washington, the only bigger export is Boeing Co.'s airplanes.

Biotechnology giants Monsanto and Syngenta have announced plans to begin testing genetically modified wheat, though the product is likely a decade or more from being offered commercially.

Resistance from the European Union and Japan led Monsanto to abandon similar efforts in 2004. Pacific Rim countries haven't historically been friendly to genetically modified products, and they remain the biggest buyers of Washington wheat.

"If we do nothing, we will be destroyed," said Tom Stahl, a fourth-generation farmer in the small town of Waterville, Wash., about 100 miles east of Seattle. "We will lose our markets and that will be devastating for the eastern Washington economy."

Monsanto and Syngenta representatives didn't immediately return messages left after a Thursday hearing on the bill.

Dozens of people testified at a packed Senate committee hearing in Olympia, Wash., where the committee chairman raised concerns about passing a bill that may conflict with federal law.

About 50 countries require genetically modified foods to be labeled, but the U.S. isn't one of them. Only Alaska has enacted legislation at the state level, requiring the labeling of genetically engineered fish and shellfish products.

Supporters said that bill was needed to protect one of Alaska's most lucrative and important industries, though genetically engineered fish are not yet on the market.

The Washington bill would require genetically engineered foods or foods containing genetically engineered ingredients to be labeled with the ingredients listed effective July 1, 2014. The rule would apply to all foods sold in the state, although those in which GM ingredients make up less than half of 1 percent would be exempt.

The federal government's position is that approved genetically modified foods are not substantially different than conventional products. Critics say requiring GM foods to be labeled will increase packaging costs and state spending on enforcement.

More than 90 percent of corn and soybeans in this country are grown from genetically modified seed, said Karen Batra, spokeswoman for the Washington, D.C.-based Biotechnology Industry Association, a trade group that advocates for biotechnology members, including Monsanto and Syngenta.

"Ultimately, you're not providing any meaningful information to consumers, because you end up labeling the majority of products," she said by telephone. "Consumers already have a choice: If they don't want biotech foods, they can buy organic."

Batra declined to speculate on whether opponents would challenge the bill in court if it passed.

Wheat has lagged behind other crops in terms of innovation, and biotechnology offers tools to deal with problems like drought and increase sustainable production, said Jane DeMarchi, the National Association of Wheat Grower's director of government affairs for research and technology.

DeMarchi said in a telephone interview that her group has been talking to people who buy wheat, including those overseas, to determine what they want from U.S. farmers and educate them about genetically modified wheat.

She said she recognized the farmers' concerns but stressed that each one has a choice of what to grow and how to label it.

"We support voluntary labeling of food products, provided it's consistent with U.S. law and trade agreements and that it's truthful and not misleading," she said.

The problem with voluntary labeling is that it puts the burden on companies whose products aren't a problem, said Trudy Bialic, director of public affairs for PCC Natural Markets, the largest consumer owned and operated grocery retailer in the U.S. It supports the bill as a means of educating consumers, preserving the identity of non-GM foods and protecting export sales.

"In my view, a lot of federal law has started at the state level," Bialic said. "This has to start at a state level, because the federal government won't take it up."