The G.M.A. is facing state and local efforts to require labeling of G.M.O.s in food and beverage products.

WASHINGTON — The most important issue currently facing the Grocery Manufacturers Association is piecemeal state and local efforts to require the labeling of food and beverage products that are formulated using ingredients from genetically modified sources.

“It is our biggest priority,” said Pamela Bailey, president and chief executive officer of the G.M.A., in an interview with Food Business News.

The labeling battle is being waged on two fronts. First, the G.M.A. and several other industry groups are embroiled in a lawsuit with the state of Vermont, which has passed and is in the process of implementing a state law that would require the labeling of products made with G.M.O.s beginning on July 1, 2016.

The groups sued the state and requested a preliminary injunction be granted to halt implementation. A U.S. district court denied the request. But the court also denied the state of Vermont’s motions to dismiss issues brought up by the coalition of industry groups seeking the injunction.

Pamela Bailey, president and c.e.o. of the G.M.A.

“The process follows the timing and process laid out by the court,” Ms. Bailey said. “The state of Vermont will be filing a reply in August and oral arguments will begin sometime this fall. Our expectation is that any decision will come later this fall, but the timing is determined by the courts.”

In the meantime, she said many of the G.M.A.’s membership are looking at their supply chain and trying to figure out how they would implement the law.

“We are hearing over and over that it is much more expensive than people previously anticipated,” Ms. Bailey said. “For example, most companies ship their products outside of Vermont to a distribution center in New York, Massachusetts or New Jersey. They very rarely ship products into Vermont. In many cases, once the product reaches the distribution center the manufacturers don’t have control over the product any longer. To sort this out is a complex and, in the end, a very expensive process.”

The second front in the battle over G.M.O. labeling is in Congress. On July 23, the House of Representatives approved the Safe and Accurate Food Labeling Act of 2015 (H.R. 1599). The bill would require labeling of a food produced from a genetically engineered plant only if the Secretary of Health and Human Services determines there is a “material difference” between the food produced and its comparable food.

“We think the vote in the House was very positive,” Ms. Bailey said. “We expect the Senate to favorably act on the bill. We were very pleased with the broad bipartisan support in the house. We expect there will be action certainly this year, the sooner the better.

“We are working with a very large coalition and that is one of the reasons this legislation has been so successful. This effort is farm-to-fork in a way that has not been united before. It includes farm groups, food processors, retailers and restaurant groups that have all worked hard on this legislation.”