(Reuters) - The U.S. House of Representatives on Thursday passed a hotly debated measure that blocks any mandatory labeling of foods made with genetically engineered crops, including pre-empting a state law set to take effect next year in Vermont.

Dubbed the Safe and Accurate Food Labeling Act by supporters, but the “Deny Americans the Right to Know” or DARK Act, by opponents, the measure was approved 275-150 with 45 Democrats voting for the bill.

House passage marks a victory for food and agricultural companies that have lobbied for the bill, and a blow to opponents, which include consumer, health and environmental groups and organic food industry players.

House members had a heated debate ahead of the vote with supporters claiming GMOs are proven safe. They said mandatory labeling would burden the food industry with unwieldy and costly requirements.

Opponents countered that 64 other countries require labeling of GMO foods, the science on safety is mixed, and consumers have a right to know if their food is made with GMOs.

“It (the bill) makes it impossible for people to know what they are purchasing and eating. It is an attack on transparency,’ said Representative John Conyers Jr., a Democrat, in floor debate.

Representative G.K. Butterfield, also a Democrat, said the bill would require regulators to examine the safety profile of new GMO foods, replacing a voluntary consultation process, and set a national standard for voluntary GMO labeling.

“It (the bill) gives consumers certainty while taking into account the delicate balance and sheer size and complexity of the food supply chain that...is responsible for feeding the country,” Butterfield said during the floor debate.

The Grocery Manufacturers Association, which represents more than 300 food companies, has been a key architect of the bill, aiming to squelch state efforts to force labeling of GMO foods.

Opponents of the bill said they see it stalling in the Senate but supporters said they are finding growing support.

Those who want to see mandatory labeling say that among their concerns about GMO foods is a worry that the herbicide glyphosate, which is widely used on genetically modified crops, is harmful to human health. Residues of the pesticide have been detected in foods and a World Health Organization research unit earlier this year said glyphosate was “probably” cancer-causing for humans.