An amendment limiting the EPA’s ability to regulate glider kits under Phase 2 greenhouse-gas and fuel-economy rules has stalled in the U.S. House of Representatives, as its underlying bill was pulled from further consideration by House leaders because of an unrelated controversy.

The amendment was offered by Congresswoman Diane Black (R-Tenn.) in response to concerns by constituents who assemble and sell glider-kitted trucks, and some fleets that buy and use them, reports the American Truck Dealers and its parent, the National Automobile Dealers Association.

The amendment to House Resolution 2822, an appropriations bill funding the Environmental Protection Agency and other government operations, passed by voice vote on July 8.  However, the bill became snarled in the controversy over the Confederate flag, and it now appears unlikely to pass in this session, making the amendment’s fate uncertain, says ATD-NADA.

Under the amendment, EPA couldn’t use appropriated funds during fiscal year 2016 to require most gliders to use diesel that meet current exhaust emissions limits. That is one of the many provisions in the proposed Phase 2 standards requiring better fuel economy and lower emissions beginning with model-year 2018.