WASHINGTON — The food industry is likely to find a receptive Congress come January in its fight against mandatory labeling of genetically modified foods.

Republicans and Democrats on a House Energy and Commerce subcommittee questioned Wednesday whether requiring a label on any packaged food including genetically modified organisms — or foods grown from seeds engineered in labs — would be misleading to consumers since there is little scientific evidence that such foods are unsafe. The food industry has made a similar argument.

Congress has shown increasing interest in getting involved in the labeling debate as the food industry has faced a potential patchwork of state laws requiring it. The hearing previewed GOP efforts to push legislation next year that would reaffirm that such food labels are voluntary, overriding any state laws that require them. The bill, introduced by Rep. Mike Pompeo, R-Kansas, has the backing of the food industry.

Even Democrats on the panel appeared concerned about the unintended effects of requiring a GMO labeling on food packages, though they stopped short of endorsing Pompeo's bill.

Rep. Henry Waxman of California, the top Democrat on the Energy and Commerce Committee, said he is concerned that labeling could be "inherently misleading." Rep. G.K Butterfield of North Carolina, a Democrat who represents a heavily agricultural district, said he is worried the costs of labeling would be passed on to consumers. Butterfield has co-sponsored the voluntary labeling bill with Pompeo.

Rep. Frank Pallone of New Jersey, who will replace the retiring Waxman as the committee's top Democrat, said he was weighing both sides of the issue.

"If the labeling could result in higher food costs, then maybe that's not a risk we want to take," he said.

Consumer advocates pushing for the labeling say shoppers have a right to know what is in their food, arguing not enough is known about the effects of the technology. They have pushed several state efforts to require labeling, with the eventual goal of having a federal standard.

Vermont became the first state to require the labels this year, passing a law in May that will take effect mid-2016 if it survives legal challenges. Maine and Connecticut passed laws before Vermont, but those measures don't take effect unless neighboring states follow suit. Ballot initiatives that would have required labeling were narrowly defeated in California and Washington in the past two years, and an Oregon initiative on the ballot this year is in the midst of a recount.

Currently, the FDA doesn't require labeling for genetically modified foods. Michael Landa, head of the FDA's Center for Food Safety and Applied Nutrition, testified that the agency believes that engineered foods on the market now are safe. The agency has a safety review process for GMO crops but it isn't required.

Landa said the agency doesn't require labeling because it has so far found no basis to conclude that foods that are genetically modified "differ from other foods in any meaningful or uniform way or pose any different or greater safety concern than foods developed by traditional plant breeding."

Genetically modified seeds are engineered to have certain traits, like resistance to herbicides or certain plant diseases. The majority of the country's corn and soybean crop is now genetically modified, with much of that going to animal feed. Modified corn and soybeans are also made into popular processed food ingredients like corn oil, corn starch, high-fructose corn syrup and soybean oil.

Labeling advocates say the issue is about transparency, not safety. Scott Faber, head of the national Just Label It campaign, testified that consumers want to know what they are buying and how the food was produced. He said advocates are not seeking a warning label, but a "factual, non-judgemental disclosure" on the back of all food packages that contain GMO ingredients.

"Because our food choices dramatically shape our lives, unprecedented consumer interest in food is a trend that should be welcomed, not frustrated," Faber said.

The food industry has faced pressure from retailers as consumer awareness of GMOs has increased and the conversation about modified ingredients has grown louder. The retailer Whole Foods announced last year that it planned to label GMO products in all its U.S. and Canadian stores within five years. And some companies have decided to remove the ingredients altogether, so no labels will be necessary.

Still, mandatory labels would disrupt the supply chain, said Thomas W. Dempsey Jr., president and CEO of the Snack Food Association. GMO ingredients would have to be separated out from farm to store, creating new burdens on manufacturers, he said.

He said food companies would have three options to comply with a state labeling law like Vermont's: order new packaging, reformulate products or halt sales to the state.

"Each option is difficult, costly, time-intensive and, at worst, could eliminate jobs and consumer choice in the marketplace," Dempsey said.