The Constitution stipulates that the House and Senate cannot adjourn for longer than three days without the consent of the other body, agreed to by a concurrent adjournment resolution. Neither chamber has passed an adjournment resolution; instead both have been holding pro forma sessions every three days.

“The House and Democratic-controlled Senate were in session yesterday, and will be again on Friday,” House Republicans said in a release calling into question the legality of the appointment. “In line with decades of congressional practices, the Department of Justice has found that Congress must be in recess more than three days before a president can make an intra-session recess appointment.”

But Obama is expected to argue that GOP attempts to prevent Congress from officially recessing do not actually bar him from filling administration posts when Congress is not meeting for legislative session. The House is due back Jan. 17 and the Senate is expected to resume normal operations Jan. 23, despite the official beginning of a new session Tuesday.

Obama is scheduled to speak this afternoon in Ohio, Cordray’s home state. His nomination has been pushed strongly by Obama’s base, with many on the left urging the president for the past six months to make a recess appointment in the face of a determined Senate GOP blockade. Republicans led by Senate Minority Leader Mitch McConnell (Ky.) have taken the unusual step of filibustering the nomination not because of the nominee but because they object to the position he would hold. They have been demanding changes in the financial reform law that would alter the structure of the agency before they will allow any nominee to be confirmed.

McConnell already has signaled that Obama will pay a price for the move. He held up a slew of Obama’s nominees at the end of last year after the White House refused to agree to follow precedent in making recess appointments.