In a judicial rebuke to President Obama, a federal appeals court in Washington, D.C. has ruled that a series of "recess appointments" made by the President in 2012 violated the Constitution, because they were made when the Senate was technically still in session.

"That is the case here, and we must strike down the unconstitutional act," read the ruling, which can be seen in full here.

At issue were three appointments made to the National Labor Relations Board by the President, which came at a time when the Senate was not adjourned, even though no legislative business was being conducted on a daily basis.

Republicans immediately claimed the appointments were illegal, and for now they are on the winning side in this case.

"Allowing the President to define the scope of his own appointments power would eviscerate the Constitution’s separation of powers," the appeals court wrote.

The President has claimed his appointments were legitimate, given that the Senate was not doing any business, but instead holding very short meetings every few days, known as "pro-forma" sessions.

But that type of meeting schedule has been used for years by both parties to prevent recess appointments.

This case could next go to the U.S. Supreme Court.

Today's appeals court ruling also raises questions about the recess appointment of Richard Cordray, who was installed as head of the Consumer Financial Protection Bureau.