The court acknowledged that the ruling conflicts with what some other federal appeals courts have held about when recess appointments are valid, which only added to the likelihood of an appeal to the high court.
"I think this is a very important decision about the separation of powers," said Carl Tobias, a constitutional law professor at Virginia's University of Richmond. "The court's reading has limited the president's ability to counter the obstruction of appointments by a minority in the Senate that has been pretty egregious in the Obama administration."
The ruling also threw into question the legitimacy of Obama's recess appointment of Richard Cordray to head the Consumer Financial Protection Bureau. Cordray's appointment, made on the same date, has been challenged in a separate case.
Carney insisted the court's ruling affects only a single case before the labor board and would have no bearing on Cordray's appointment. Obama on Thursday renominated Cordray for the job.
The case challenging the recess appointments was brought by Noel Canning, a Washington state bottling company that claimed an NLRB decision against it was not valid because the board members were not properly appointed. The D.C. Circuit panel agreed.
Obama made the recess appointments after Senate Republicans blocked his choices for an agency they contended was biased in favor of unions. Obama claims he acted properly because the Senate was away for the holidays on a 20-day recess. The Constitution allows for such appointments without Senate approval when Congress is in recess.
But during that time, GOP lawmakers argued, the Senate technically had stayed in session because it was gaveled in and out every few days for so-called pro forma sessions.
GOP lawmakers used the tactic — as Democrats had done in the past — specifically to prevent the president from using his recess power to install members to the labor board and the consumer board. They had also vigorously opposed the nomination of Cordray.