A Washington federal appeals court on Thursday weighed a challenge to an Obama-era labor rule that let employees speed up how quickly they hold union elections.

A panel of the U.S. Court of Appeals for the D.C. Circuit considered an appeal from UPS Ground Freight Inc. that challenges a bargaining unit certified by a regional director of the National Labor Relations Board. The labor board's adoption of the so-called “quickie” or “ambush” election rule in 2015 drew cries from the business community.

Business advocates, who filed a friend of the court brief backing UPS, are closely following the D.C. Circuit case, which they contend is an example of a federal agency acting outside the scope of its power. The U.S. Chamber of Commerce, in its brief, urged the federal appeals judges not to give “deference” to the labor board.