Updated: 5:07 p.m.

The Department of Justice released a 23-page legal opinion today that backs President Barack Obama’s authority to make recess appointments and ignore pro forma sessions of the Senate — but it failed to satisfy GOP critics.

The opinion from the Department’s Office of Legal Counsel is dated Jan. 6, two days after the president bypassed the Senate to appoint Richard Cordray to be the director of the Consumer Financial Protection Bureau and named three people to the National Labor Relations Board. White House Press Secretary Jay Carney said today that the Justice Department had verbally advised in advance of the appointments that they were legal.

The opinion contends that pro forma sessions in which no business is conducted do not have the legal effect of ending a recess of the Senate.

“In this context, the president therefore has discretion to conclude that the Senate is unavailable to perform its advise-and-consent function and to exercise his power to make recess appointments,” the opinion states.

The Justice Department opinion also cited an early opinion during the waning days of the George W. Bush administration that the president could ignore pro forma sessions to make appointments — although the Bush administration opted not to do so.

Senate Judiciary ranking member Chuck Grassley (R-Iowa) called the opinion “unconvincing” and at odds with the Constitution.

“It fundamentally alters the careful separation of powers between the executive and legislative branches that the framers crafted in the Constitution. … This is clearly an escalation in a pattern of contempt for the elected representatives of the American people. The Senate will need to take action to check and balance President Obama’s blatant attempt to circumvent the Senate and the Constitution.”

The Heritage Foundation also ripped the legal opinion in a blog post.

“Who is the president to judge whether the Senate is ‘doing enough’ for its proceedings to qualify as a recess?” asked Todd Gaziano, director of the foundation’s Center for Legal & Judicial Studies.

Gaziano highlighted the contention in the memo that the “Senate may choose to remain continuously in session and available to exercise its advice-and-consent function” and defeat the president’s recess appointment power. “Under OLC’s new, new advice, must 51 Senators remain in their seats in the Senate chamber at all times? Or must they at least sleep in their offices, or within range [of] a 15-minute quorum call? Apparently, the president has unilateral authority to determine that.”

Earlier this week, 72 House Republicans introduced a nonbinding resolution voicing concern with the appointments, and some expect the appointments to be challenged in court.