In cities across the globe, including Los Angeles, tens of thousands of protesters turned out Saturday for the March Against Monsanto, producer of genetically modified seeds.

PHOENIX - Saying people are entitled to know what they're eating, a Tucson activist has taken the first steps to force a public vote next year to require labeling of foods with genetically modified ingredients.

Jonathan McLane said he has concerns about whether plants whose genes have been modified are safe to consume. He said there hasn't been enough research to determine long-term effects.

But McLane said whether or not the products are safe is not the issue right now. And nothing in his measure would ban the sale of such foods.

It would simply require a notation on labels saying the product contains genetically modified organisms.

"People have a right to know exactly what's in their food," he said.

McLane has until July 3, 2014, to gather 172,809 valid signatures to force the issue onto the ballot.

The campaign is going to get a fight from the agriculture community, just as it did last year in California when a similar measure was beaten back by voters, 53-47 percent.

Julie Murphree, spokeswoman for the Arizona Farm Bureau Federation, said it's not because her organization is against consumers being informed.

She said products that are certified by the U.S. Department of Agriculture as organic already are labeled as not including genetically modified organisms, or GMOs, as they have been called. And other manufacturers already are free to slap "GMO-free" labels on their products.

It's the connotations of labeling that concern her.

"Mandatory GMO food labeling implies risk where there really is none," she said. "If you label that non-GMO, it's 'Oh, GMO foods must be unhealthy and evil,' and they're not."

That's also the position of agribusiness giant Monsanto, which produces and sells many of the genetically modified seeds for crops that end up in the food supply.

"We oppose current initiatives to mandate labeling of ingredients developed from GM seeds in the absence of any demonstrated risks," the company said in a prepared statement. "Such mandatory labeling could imply that food products containing these ingredients are somehow inferior to their conventional or organic counterparts."

Murphree said there have been multiple studies showing the body treats and breaks down genetically modified grains or produce exactly the same as those products without GMOs.

But McLane said consumers, not food companies, should be making the decision on what we should know about what we put into our bodies.

And he said nothing prohibits a company from using the label "natural" on the box even if it contains GMO products.

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Murphree said those who are concerned can buy USDA-certified organic products and know they are not getting anything made with GMOs.

That still raises the question of what information consumers are entitled to get.

Murphree acknowledged there are laws that require each ingredient to be listed, right down to various colors and dyes that scientists say are natural or, at least, not harmful. But she said that's "not a comparable parallel."

Part of the issue for the industry, Murphree said, is cost. She said it could require companies to have separate processing lines for handling GMO and non-GMO foods to ensure compliance with labeling laws.

She also argued that those concerned about GMOs in food, from a health perspective, are focused on the wrong thing.

"We're getting our eyes off the ball," Murphree said. "The ball is, we need to eat more balanced diets. We need to eat more fruits and vegetables. And we need to stay away from too much sugar and too much fat."

No state has yet enacted such a labeling law. But while California voters defeated the law there, the Connecticut Senate, voting 35-1, approved a labeling requirement earlier this month. That followed similar action in the Vermont House.

In Arizona, Sen. Ed Ableser, D-Tempe, introduced his own plan earlier this year to require "the clear and conspicuous words 'genetically engineered' on the front of the package" of any product entirely or partly produced with genetic engineering, but his bill never got a hearing.

McLane said he was previously involved with Occupy Tucson.