(Bloomberg News) Californians are on course to vote whether genetically modified food must be labeled following a campaign that has targeted Monsanto Co. and other biotech-crop companies.

Proponents of the measure collected 971,126 signatures, 75 percent more than the minimum needed for a statewide referendum concurrent with the Nov. 6 general election, the Oakland-based California Right to Know campaign said today in a statement. State certification of the signatures followed by approval from 50 percent of voters would make the proposal law.

"The right to know is as American as apple pie," Gary Ruskin, an Oakland-based manager for the campaign, said in an April 30 interview. "Monsanto and some other chemical and agricultural biotech companies are desperate to keep the public in the dark about what is really in their food."

The California movement is mobilizing consumer unease over modified ingredients, which are found in about 80 percent of processed foods in the U.S. according to the Grocery Manufacturers Association. The campaign is the best chance for biotech labeling in the U.S. after the failure of similar bills in 19 states and the rejection of a petition to the Food and Drug Administration last month, Ruskin said.

Monsanto opposes labeling modified ingredients because the move risks "misleading consumers into thinking products are not safe when in fact they are," Sara E. Miller, a spokeswoman for St. Louis-based Monsanto, said in an e-mail.

'Back Door'

The initiative is a "back door" way to hurt the $13.3 billion biotech crop industry, according to Richard Lobb, managing director for the Council for Biotechnology Information.

"They basically are trying to scare consumers through labeling," Lobb, whose Washington-based group represents developers of biotech seeds including Monsanto and DuPont Co., said in a telephone interview. "The obvious objective is to push biotechnology out of the market altogether."

Biotech labeling, which has been adopted in more than 40 countries, has never been endorsed by the FDA. The agency says crops engineered to tolerate herbicides or produce insecticide pose no greater health risks than conventional foods.

Modified foods have been in U.S. grocery stores since 1994. Ninety-three percent of Americans say genetically engineered foods should be labeled, according to an October 2010 poll conducted by Thompson Reuters Corp. and National Public Radio. Seventy-nine percent have doubts about the safety of such foods, according to the poll.

Label Exemptions

Food labels should be reserved for "critically important food safety and nutritional information," said Brian Kennedy, a spokesman for the Grocery Manufacturers Association, which opposes the California initiative. His group donated $375,000 to fight the ballot proposal, matching the amount provided by the Council for Biotechnology Information, according to public disclosures.

Should it be approved, the measure would require labels of foods made with biotech ingredients to state that they were "produced with genetic engineering." Labels would be phased in over 18 months. Exemptions include restaurant food, alcohol and meat from animals fed with modified grains.

The label "would be the equivalent of a skull and crossbones" that would drive away customers and force food producers to stop using engineered ingredients, Joseph Mercola, the inititive's leading funder with $800,000 in donations, said in an April 1 Web posting. Mercola is an osteopath who promotes natural remedies at his clinic in Hoffman Estates, Illinois.

Chris Shaw, a New York-based analyst at Monness Crespi Hardt & Co. who recommends selling Monsanto shares, said labels identifying genetically modified organisms, or GMOs, won't change most consumers' buying decisions.

"People who are buying Oreos aren't going to care if there is GMO soybean oil in there," Shaw said. "It's going to be a marginal group of people that will care."