U.S. Sen. Mike Johanns along with 41 other senators has filed an amicus brief in a challenge to challenge constitutionality of President Obama’s “recess” appointments to the National Labor Relations Board in January. Republicans argue that the Senate was still in session, not in recess, making the Presidents appointments illegal.

Obama made the appointments whilst Senators were still on their Christmas and New Year break, and the Senate was operating on a pro forma basis. Obama therefore decided the Senate was on recess.

If the appeals court sides with the Republicans it could invalidate a host of decisions already passed by the National Labor Relations Board.