The U.S. Congress voted last year to stop horse slaughter for human consumption for 2006 with a back-door effort, through an amendment to the Food and Drug Administration Appropriations Act.

Instead of outlawing horse slaughter, they voted to stop funding FDA inspectors for the slaughter plants. Cutting off the funding was meant to end horse slaughter, because federal law requires the inspections. The act is supposed to go into effect March 10.

But owners of the three foreign-owned U.S. slaughter plants—in Texas and Illinois—were quick to find a way around the new legislation. They petitioned to pay for the inspections themselves, rather than depend on government funding, similar to the system of inspections for elk and other exotic animals.

And FDA officials announced approval for that plan on Feb. 7, leaving many Congressmen sputtering in anger.

“We were shocked and deeply upset to learn that [the FDA] has apparently decided it need not carry out Congress’ clearly expressed intent to halt horse slaughter for human consumption in FY 2006,” states a letter written on Jan. 17 and signed by 40 senators and representatives to Mike Johanns, U.S. Secretary of Agriculture.

“In a gross misrepresentation of this clearly expressed intent, your general acting counsel has suggested that ‘section 794 does not prevent horse slaughter at all,’ and has shared the agency’s plan to continue horse slaughter under a ‘fee-for-service’ arrangement pursuant to a convoluted interpretation of an entirely different federal law,” the letter continued.

“As required by the 2006 Amendment, the agency must cease inspection of horses for slaughter. Failure to do so constitutes willful disregard of clear Congressional intent on the part of the USDA,” ends the letter.

Johanns hasn’t responded publicly to the letter.