Across the globe, 61 countries, including China, the European Union's 27 members and even Syria, label genetically modified foods.

But in America, consumers are left in the dark about which foods and products contain genetically modified (GMO) ingredients.

That may change soon, though, as nearly half of the nation’s state legislatures, according to the Center for Food Safety, have introduced bills to require manufacturers to label foods containing genetically modified or genetically engineered products.

The U.S. Congress, meanwhile, is headed in the other direction, as an amendment to the 2013 Farm Bill passed by the House Agriculture Committee last week would revoke the rights of states to pass such GMO-labeling laws, food advocates warn.

The labeling of genetically modified food is ground zero in the controversy over GMOs made by companies like Monsanto (NYSE:MON) and Dupont (NYSE:DD), and the issue is likely to grow even more divisive as food safety groups butt heads with Congress and Big Ag over the right to know what's on our plates.

Among the states making major strides toward passing GMO-labeling legislation are Oregon, Connecticut and Vermont, whose House of Representatives passed such a bill earlier this year. Vermont’s legislature has two-year sessions, so if the state Senate passes it next year, and Gov. Peter Shumlin signs it, it will become state law.

The lead sponsor of the bill, known as H 112, is state Rep. Kate Webb, a Democrat who argues that the public should have access to as much information as possible about the food they eat.

“What the bill would do is require, generally speaking, that products that contain items that have been produced through genetic engineering would need to be so labeled,” Webb said. “The groundswell has just gotten large enough that people are concerned. It’s the right to know; it’s the right to make decisions about the food that you eat.”

The science is still inconclusive on whether genetically modified and genetically engineered foods are harmful to humans, but supporters of GMO labeling point to studies showing a range of potential risks, from kidney and liver damage to reproductive system issues.

Webb said she is aware that GMO-producing companies will certainly challenge any such bill in court -- she said a lobbyist representing the biotech industry said last year to “expect litigation if it passes” -- but that she believes H 112 has been crafted in such a manner that it would have a good chance of being upheld before a federal court or the U.S. Supreme Court if passed.

“We have three legal hurdles: These are federal pre-emption, First Amendment rights and the Interstate Commerce Clause, and we have worked with expert testimony that indicates we have a reasonable chance to prevail,” she explained. “We can’t say what the courts will do, but the way the bill is crafted, we believe that we have demonstrated that the state has a legitimate interest in this labeling.”

Not everyone in Vermont’s Legislature is so bullish about the bill’s chances, however, including state Rep. Tom Koch, a Republican with many years of experience as an attorney.

Koch said he supports the bill’s goals, but he argued that the financial burden on taxpayers of defending it in court would be prohibitive and gave that as the reason he and many of his colleagues opposed it earlier this year.

“I believe in consumer information and disclosure and consumer choice and I join people who say they want to know what’s in their food so they can make an intelligent choice, and I think we had a good bill,” Koch said. “The only problem I have with it is that I’m sure it will be challenged in court and will cost probably a couple million dollars to defend it, win, lose or draw. And that’s my problem. I think we have a good chance of losing.”

He said he would rather see another state pass a similar bill first, so that the approximately 626,000 residents of Vermont can avoid the cost of a lengthy court battle. If such a bill passed in another state were to prevail in the courts, then he would support a GMO labeling bill for the Green Mountain State.

“My attitude is, let Oregon go first, let them be sued, let them pay the fees, and if they’re successful in court, then I’m all for adopting this bill. But I don’t see why Vermont should go first and spend taxpayers’ money in this effort for Vermont to lead the nation,” he explained. “You can never predict what a court will do absolutely, but you can rate your chances. I don’t like our chances in this case, and that’s why I oppose this bill.”

Still, efforts by states to enact their own GMO-labeling requirements may be for naught if the 2013 Farm Bill passes as it currently stands.

The bill was passed by the House Agriculture Committee last week with an amendment dubbed the Protect Interstate Commerce Act (PICA) that would likely put an end to state-level efforts to require GMO labeling.

Here’s how Rep. Steve King, an Iowa Republican, described the amendment in a Wednesday statement:

"The first King amendment prohibits states from enacting laws that place conditions on the means of production for agricultural goods that are sold within its own borders, but are produced in other states," he wrote.

That description may make the amendment sound like an innocuous attempt to prevent states from infringing on one another’s rights. But critics of the amendment warn that the bill is actually a thinly veiled attempt to undermine the ability of states to enact GMO-labeling regimes.

The Organic Consumers Association on Wednesday put out a strongly worded statement calling on Congress to reject PICA.

"The biotech industry knows that it’s only a matter of time before Washington State, Vermont, Maine, Connecticut and other states pass GMO labeling laws," the group wrote. "Rather than fight this battle in every state, Monsanto is trying to manipulate Congress to pass a Farm Bill that will wipe out citizens’ rights to state laws intended to protect their health and safety.”

It remains to be seen whether PICA will remain a part of the 2013 Farm Bill and move on to pass the Senate and be signed by the president. But the provision has become a flashpoint in the continuing debate over the use of GMOs in American food and crops.

Meanwhile, Sen. Barbara Boxer, D-Calif., has taken the opposite tack, introducing a bill in April dubbed the Genetically Engineered Food Right-to-Know Act, aimed at requiring the Food and Drug Administration to label such foods.

“Americans have the right to know what is in the food they eat so they can make the best choices for their families,” Boxer said in a statement announcing the bill, known as S.809. “This legislation is supported by a broad coalition of consumer groups, businesses, farmers, fishermen and parents who all agree that consumers deserve more – not less – information about the food they buy.”

The bill has gained the support of 10 co-sponsors, including a couple of Republicans, and a version has been introduced in the House, but both bills have remained in committee since they were introduced.

As the controversy over GMOs grows ever more heated, many Americans will be watching closely as legislators hash out the best way to address the issue. It remains to be seen whether GMO labels will ever appear on grocery store shelves in America.