The National Association of Manufacturers on Friday was handed a major defeat in its challenge to a provision in the lobbying reform law that it said violated its constitutional rights.

In a 57-page ruling, Judge Colleen Kollar-Kotelly of the U.S. District Court for the District of Columbia dismissed in its entirety NAM’s challenge to the disclosure provision.

At issue in the case was a piece of the Honest Leadership and Open Government Act aimed at forcing so-called stealth lobbying coalitions — those groups that exist only on paper to hide their financial backers — to disclose their members.

The measure requires coalitions to report any organization that contributes at least $5,000 per quarter and actively participates in shaping lobbying campaigns.

But NAM contended the measure would force it to disclose its membership, in violation of its First Amendment rights to free association.

In its ruling, the court found that contrary to NAM’s argument, the provision “is narrowly tailored to serve compelling government interests, and is neither vague on its face nor as applied to the NAM.”

Democracy 21 President Fred Wertheimer, whose group filed an opposing brief in the suit, said, “We’ve always believed that this lobbying disclosure provision was constitutional and the NAM case was without merit. We are pleased that the district court judge reached the same conclusion and dismissed the case.”

NAM officials could not be reached for comment Friday evening, and it was not known whether the group would appeal the ruling.

— Tory Newmyer