Scott Smith tosses a fresh salmon to a colleague behind the counter at the Pike Place Fish Market in Seattle in October 2010. In television ads featuring Pike Place Market fishmongers, organic farmers and others, supporters have hammered the consumer’s right to know whether the foods they buy were produced with genetic engineering, noting it’s not different from other food labels. (Elaine Thompson/AP)

Flip on a television anywhere across Washington state, and within minutes the barrage of advertisements makes this much clear:

The latest fight over whether to require companies to label foods containing genetically modified ingredients has turned expensive and polarizing — not to mention perplexing for many people.

On Tuesday, residents will vote on Initiative 522, which would force manufacturers to disclose their use of genetically altered crops such as corn and soy, which are widely used in processed foods.

If the initiative is approved, Washington will become the first state to pass such labeling requirements. The outcome could have broad implications for the rest of the country, where the issue has demanded increasing attention in recent years. Dozens of states have begun to consider legislation requiring genetically modified foods to be labeled, and a measure similar to I-522 failed in California last year after a bruising fight between activists and the food and industrial agriculture industries.

The vote in Washington has attracted record amounts of money — much of it from outside the state — from consumer activists who favor the measure and from biotech and food giants, such as Monsanto, PepsiCo and General Mills, that oppose the labeling requirement.

Patty Lovera of consumer rights groups Food & Water Watch explains what labeling genetically modified products could mean for your wallet. (The Washington Post)

Supporters of labeling have framed the vote as an issue of consumer choice and transparency. They note that scores of other countries have required labeling of genetically altered foods and say the United States should follow suit, given that as much as 80 percent of packaged foods in the country include genetically modified ingredients.

“People have a right to know what is in their groceries,” said Elizabeth Larter, a spokeswoman for the Yes on 522 campaign. “This is about letting you and me decide, and not having this information concealed from us. . . . We should be more transparent in our food system.”

Opponents have attacked the initiative as complex, costly and rife with exemptions; restaurants, for example, wouldn’t be subject to the labeling requirement. They argue that voluntary labels already exist for consumers seeking foods without genetically modified ingredients and that mandating labels for all genetically modified foods would stigmatize those products. The Food and Drug Administration and the American Medical Association have said such foods are safe.

“We just don’t accept the premise that this label will provide consumers with any material information. In fact, it would be inherently misleading,” said Louis Finkel, executive vice president for the Grocery Manufacturers Association (GMA) a food-industry trade group that has poured more than $11 million into fighting I-522. “There’s no scientific evidence backing the need for a special label.”

The dispute has led to the most expensive ballot initiative campaign in the state’s history, with potential voters besieged by a stream of ads on television, on the Web and in their mailboxes.

But the spending has proved anything but equal, according to Washington State Public Disclosure Commission records.

Proponents of labeling genetically modified food have raised more than $7 million. Some of that money has come from advocacy groups such as the Center for Food Safety and companies such as Dr. Bronner’s Magic Soaps, which has given more than $2 million. But the rest has come from thousands of individual donors.

Meanwhile, the No on 522 campaign has raised more than $22 million from a far smaller pool of donors, records show. They include biotech and agricultural giants such as Monsanto, DuPont Pioneer, Bayer CropScience and BASF Plant Science, which play key roles in developing and selling seeds for genetically engineered crops. By far, the largest backer of the anti-labeling campaign has been the GMA, which, after being sued by the Washington attorney general for allegedly violating state disclosure laws, agreed last month to release the names of donors funding the effort. They include Coca-Cola, Kellogg and NestleUSA.

The opponents of I-522 have far outspent supporters in recent weeks, inundating the airwaves with ads warning consumers about misleading labels and higher food costs if companies choose to turn to more expensive non-
genetically altered ingredients to avoid mandatory labels.

When veteran Seattle pollster Stuart Elway surveyed likely voters about I-522 in September, two-thirds said they were likely to vote for the labeling requirement, compared with 22 percent against. Barely a month later, after a sustained ad blitz by opponents, those numbers had shifted sharply, to 46 percent in favor and 42 percent against the proposal.

“I’ve polled 80 or so initiatives in the last 20 years, and I’ve never seen anything like this,” Elway said.

Numerous editorial boards also have lined up against the measure. The Seattle Times called I-522 “a clumsy, emotion-based campaign.” Spokane’s Spokesman-Review called it a “potentially good idea wrapped in very bad law-making.”

Charles Benbrook, a Washington State University agricultural researcher, said the activists pushing for labeling are trying to fill a void left by Congress and federal regulators, who have yet to seriously consider a national labeling system.

“This is an in­cred­ibly important vote,” Benbrook said. “Passage of I-522 will set the country on a different and hopefully more constructive path of dealing with some of these underlying tensions.”

And if it doesn’t pass Tuesday?

“Almost certainly, the gloves are going to come off for the next round,” Benbrook said. “And the poor public is going to just get more confused.”

Finkel, of the GMA, said the group will continue to “provide the resources” necessary to oppose the push for labeling requirements in Washington state, just as it has in California and elsewhere.

“We’ve opposed them around the country. We will continue to oppose these mandatory labels,” he said. “Our financial support has been to ensure consumers have that information about what the impact is going to be. . . . We believe this is a bad measure that’s not in the best interest of consumers.”

For their part, activists hope a victory Tuesday eventually could help force more action from officials in Washington, D.C.

“There are millions of Americans who want this information,” said Larter, of Yes on 522. “Whether we win or lose here, this movement will continue to go on.”