A federal judge has invalidated a new National Labor Relations Board rule that advocates say simplifies the process for workplace unionization elections, but opponents contend makes it harder for employers to prepare for those contests.

In his May 14 decision, Judge James E. Boasberg of the U.S. District Court  for the District of Columbia concluded that the NLRB did not have the  necessary three-member quorum when it voted in December to approve the  regulation. Boasberg did not rule on the merits of the rule.

The regulation, which went into effect on April 30, does away with pre-election appeals of NLRB regional officials’ decisions regarding union-representation elections. It instead consolidates those regional appeals into a single post-election request for review.

In December, a coalition of business groups—including the Associated Builders and Contractors and Associated General Contractors of America—filed a lawsuit challenging the regulation, which they said would harm employers by reducing the time frame for union elections.

Although the NLRB’s two Democratic members voted in favor of the changes, Republican Member Brian Hayes, who opposed the rule, did not cast a vote. “Two is simply not enough,” Boasberg wrote. “Member Hayes cannot be counted toward the quorum merely because he held office, and his participating in earlier decisions relating to the drafting of the rule does not suffice.”

Boasberg also said that “nothing appears to prevent a properly constituted quorum of the board from voting to adopt the rule if it has the desire to do so. In the meantime, though, representation elections will have to continue under the old procedures.”

Nancy Cleeland, an NLRB spokeswoman, said on May 15 that the board was  reviewing the decision and did not have an immediate comment.

Business groups are claiming victory. Geoff Burr, Associated Builders  and Contractors vice president of federal affairs, says, “We said all  along that the ‘ambush’ elections rule was made in haste, without regard  or consideration to the proper procedures, and that the rule would have  a negative impact on the nation’s small businesses.”

But Senate Health, Education, Labor and Pensions Committee Chairman Tom Harkin (D-Iowa) hinted that an appeal is likely. Harkin said in a statement that the ruling suggests that “an individual board member should have veto power over any NLRB decision,” which he said is contrary to the law. “I am confident that when the courts reconsider this issue, they will correct this error,” Harkin added.