The Supreme Court has been asked to take emergency action over the validity of President Barack Obama's appointments to an independent agency, which were struck down by a lower court as an unconstitutional use of executive power.
The case sets up a potential high-stakes fight between the executive and legislative branches over so-called recess appointments, a common tactic used by Democratic and Republican administrations to temporarily put people in jobs without Senate confirmation.
A federal appeals court in Washington concluded unanimously last month that three recess appointees to the National Labor Relations Board lacked authority to serve because the Senate was technically in session when they were placed on the panel in 2012.
The ruling, if upheld, could invalidate hundreds of findings by the board issued over the past year.
The decision also could jeopardize the recess appointment of Richard Cordray to head the Consumer Financial Protection Bureau, a major administration priority that grew out of the Wall Street reform law.
The labor board appointments were challenged in a suit brought by Noel Canning, a family-owned Yakima, Washington, bottling company, which complained the NLRB unfairly ruled in favor of Teamsters Local 760 during contract negotiations.
Company executives said the board lacked a binding quorum because the recess appointments made by Obama were not legal.
The five-member board has been politically polarized in recent years as it moved from a Republican to Democratic majority. Republicans claim the board is overly pro union.
The White House said it believed the decision would not affect Cordray's appointment, but did express displeasure with the court's action.
"The decision is novel and unprecedented. It contradicts 150 years of practice by Democratic and Republican administrations," said White House Press Secretary Jay Carney after the ruling.
The appeals court said that allowing a president to "define the scope" of his powers over appointments would violate the Constitution's separation of powers.
"An interpretation of 'the recess' that permits the president to decide when the Senate is in recess would demolish the checks and balances inherent in the advice-and-consent requirement, giving the president free rein to appoint his desired nominees at any time he pleases, whether that time be a weekend, lunch, or even when the Senate is in session and he is merely displeased with its inaction. This cannot be the law."
Senate Republicans applauded the decision.
"The (court ruling) reaffirmed that the Constitution is not an inconvenience but the law of the land, agreeing with the owners of a family-owned business who brought the case to the Court," Senate Minority Leader Mitch McConnell said in a statement.
Legal experts have disagreed on both the tactical and timing procedures by the Senate, and whether the President has unilateral authority to override those legislative tactics.