Supporters of an initiative that would require labeling of genetically engineered foods say consumers have the right to know more about what they eat and farmers have the right to preserve their market share in the global economy.

Opponents counter that such a step is unnecessary, because genetically engineered foods are healthy, and consumers already have the option not to purchase them by buying organic.

People on both sides of Initiative 522 lined up to offer testimony to a state lawmakers Thursday in Olympia. The ballot initiative would require food and seeds produced entirely or partly through genetic engineering and sold in Washington to be labeled as such, beginning July 1, 2015. Raw foods that are not packaged separately would have to be labeled on retail shelves.