Pacelle compared King's amendment to "legislative kudzu, so invasive and dangerous it could crowd out hundreds of state and local laws setting appropriate standards for agriculture."
Further, he noted that the amendment would prevent states' rights to impose "reasonable standards" on agriculture to protect animals, workers, the environment and consumers.
A group of lawmakers are also joining in to back HSUS' position, noting in a letter to House Ag Committee Ranking Member Collin Peterson, dated Aug. 2, that the amendment could repeal laws that cover food safety and environmental protection, not just farm animals.
"For example, labeling and other rules for products and ingredients such as artificial sweeteners, maple syrup, milk fat, farm-raised fish, tobacco, and additives in alcohol could be swept away," the group said.
Additionally, they claimed that it could present a hurdle to cross in the grand scheme of farm bill negotiations.
"The King amendment represents an additional layer of serious controversy on already controversial legislation. As you work with colleagues to develop a final Farm Bill package for consideration by the House and to find sufficient votes to pass it, we strongly urge you to do all you can to keep out the King amendment and any provision like it," they said.
The amendment has already seen significant debate during House markup of the farm bill, though it passed on a voice vote.