In this photo, U.S. Deputy Attorney General Sally Quillian Yates testifies during a Senate Judiciary Committee hearing on "Going Dark: Encryption, Technology, and the Balance Between Public Safety and Privacy" in Washington, July 8, 2015. REUTERS/Kevin Lamarque

UPDATE: 9:45 p.m. EDT — The White House moved swiftly to replace Acting Attorney General Sally Yates for questioning the legality of the executive order banning immigrants from seven countries. White House spokesman Sean Spicer said Dana Boente, the U.S. attorney in Richmond, Virginia, would take over leadership of the Justice Department until Jeff Sessions is approved as attorney general by the Senate.

In a Facebook post, President Donald Trump said Yates had "betrayed the Department of Justice by refusing to enforce a legal order."

UPDATE: 8:50 p.m. EST — Former Attorney General Eric Holder praised Acting Attorney General Sally Yates as a person of integrity, saying her judgment should be trusted.

UPDATE: 7:55 p.m. EST — President Donald Trump reacted angrily to Acting Attorney General Sally Yates' decision against enforcing his executive order on immigrants from seven countries, tweeting Democrats were delaying his Cabinet picks for "purely political reasons."

Original story

Acting Attorney General Sally Yates, a holdover from the Obama administration, Monday ordered Justice Department lawyers not to defend President Donald Trump’s executive order barring immigrants from seven Muslim-majority countries, saying she did not believe the order was “lawful.”

Yates decision comes a day before likely Senate confirmation of Jeff Sessions as attorney general and could provoke a confrontation with the White House.

Trump signed an executive order Friday barring immigration from Syria indefinitely and for at least 90 days from Iran, Iraq, Libya, Somalia, Sudan and Yemen. He also suspended the U.S. refugee program for at least 120 days.

At least four federal judges moved to block the order late Saturday and early Sunday, and the White House spent the weekend trying to clarify exactly who was covered.

Yates, a career prosecutor and former U.S. attorney in Atlanta before being appointed deputy attorney general, sent an email to Justice Department lawyers, saying she had serious concerns about the order’s legality and instructing them not to appear in court on behalf of the administration.

"My responsibility is to ensure that the position of the Department of Justice is not only legally defensible but is informed by our best view of what the law is after consideration of all the facts," she said. "In addition, I am responsible for ensuring that the positions we take in court remain consistent with this institution's solemn obligation to always seek justice and stand for what is right."

"At present, I am not convinced that the defense of the executive order is consistent with these responsibilities nor am I convinced that the executive order is lawful," she wrote.

In addition to the emergency orders handed down during the weekend in Virginia, New York, Massachusetts and Washington state, a fifth case is pending in California.

Thousands of people demonstrated at U.S. airports during the weekend to protest the order, which many see as running counter to U.S. values. Democrats held a protest on the steps of the Supreme Court Monday to protest the order.