WASHINGTON -- President Barack Obama violated the Constitution when he bypassed the Senate last year to appoint three members of the National Labor Relations Board, a federal appeals court ruled Friday in a far-reaching decision that could severely limit a chief executive's powers to make recess appointments.The decision by the U.S. Court of Appeals for the D.C. Circuit marked a victory for Republicans and business groups critical of the labor board. If it stands, it could invalidate hundreds of board decisions over the past year, including some that make it easier for unions to organize.When Obama filled the vacancies on Jan. 4, 2012, Congress was on an extended holiday break. But GOP lawmakers gaveled in for a few minutes every three days just to prevent Obama from making recess appointments. The White House argued that the pro forma sessions -- some lasting less than a minute -- were a sham.The court rejected that argument but went even further, finding that under the Constitution, a recess occurs only during the breaks between formal yearlong sessions of Congress, not during just any informal break when lawmakers leave town.It also held that presidents can bypass the Senate only when administration vacancies occur during a recess.White House press secretary Jay Carney said that the administration strongly disagrees with the decision and that the labor board will conduct business as usual despite calls by some Republicans for the board members to resign."The decision is novel and unprecedented," Carney said. "It contradicts 150 years of practice by Democratic and Republican administrations."Under the court's decision, 285 recess appointments made by presidents between 1867 and 2004 would be invalid.The Justice Department hinted that the administration will ask the Supreme Court to overturn the decision, which was rendered by three conservative judges appointed by Republican presidents. "We disagree with the court's ruling and believe that the president's recess appointments are constitutionally sound," the statement said.The court acknowledged that the ruling conflicts with what some other federal appeals courts have held about when recess appointments are valid. That 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 throws 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 that the court's ruling affects only a single case before the labor board and has no bearing on Cordray's appointment. Obama renominated Cordray for the job Thursday.The case challenging recess appointments was brought by Noel Canning, a Washington state bottling company. It said a labor board decision against it is invalid because the 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 that they contended was biased in favor of unions. Obama says 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 have in the past -- specifically to prevent the president from using his recess power to install members on the labor board and the consumer board.They had also vigorously opposed the nomination of Cordray.