WASHINGTON — The House Judiciary Committee voted Wednesday to advance a measure that would hold Attorney General William Barr in contempt of Congress after President Donald Trump asserted executive privilege over special counsel Robert Mueller's unredacted report.

"We are in a constitutional crisis," Chairman Jerrold Nadler, D-N.Y., told reporters after the vote. "We are now in it."

Nadler said lawmakers were concerned that the president's decision to assert executive privilege "is going to have a chilling effect or more" on other issues relating to investigations into Trump and his administration. While Nadler said that impeachment "may not be the best answer," he didn't rule out such action.

The Justice Department pushed back. "Nadler’s actions have prematurely terminated the accommodation process and forced the President to assert executive privilege to preserve the status quo," spokeswoman Kerri Kupec said in a statement. "No one, including Chairman Nadler and his Committee, will force the Department of Justice to break the law.”

Moving to hold Barr in contempt for refusing to comply with the committee's subpoena for the full, unredacted report and its underlying evidence is "not a step we take lightly," Nadler said Wednesday, but rather the "culmination of nearly three months of requests, discussions and negotiations with the Department of Justice."

"I am concerned that the department is heading in the wrong direction,” Nadler said, adding that minutes earlier, Trump took the “dramatic step” of exerting executive privilege. "This is unprecedented. If allowed to go unchecked, this obstruction would mean the end of congressional oversight."

The White House announced Trump's decision to assert privilege just as lawmakers were beginning discussion around the contempt resolution Wednesday morning. Faced with Nadler's "blatant abuse of power," Trump "has no other option than to make a protective assertion of executive privilege," press secretary Sarah Sanders said in a statement.

The moves represent a major escalation of the battle between congressional Democrats and the president. It will likely lead to a protracted legal war over Mueller's 448-page report on the alleged obstruction of justice by Trump and the Russian interference in the 2016 U.S. election.

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Before voting 24-16 along party lines to approve the contempt resolution, members of the Judiciary Committee spent almost seven hours Wednesday discussing the measure, as well as a supporting 27-page report in which Democrats raised the prospect of impeachment as a result of their investigation relating to the Mueller probe.

Rep. Sheila Jackson Lee, D-Texas, said that the collapse of negotiations between Barr and the committee, as well as Trump's assertion of privilege, brought her to only one conclusion: "that the president now seeks to take a wrecking ball to the Constitution of the United States of America."

Later, Rep. Hank Johnson, D-Ga., said that once the committee obtains the documents it needs, it can move forward, including on the issue of impeachment, prompting Rep. Matt Gaetz, R-Fla., to shoot back that Democrats' efforts were all about impeaching the president.

Republicans, meanwhile, accused the Democrats of rushing the oversight process and alleged that members were afraid of the investigations Barr has suggested he may initiate into surveillance practices under the Obama administration.

Rep. Doug Collins, R-Ga., the committee's ranking member, said Democrats were acting in haste because they are "angry" that "the special counsel's report did not produce the material or conclusions they expected to pave their path to impeaching the president" — sullying Barr's reputation in the process.

"I ask you to recognize that craven and insincere politics yield anemic dividends for Americans who have asked us to legislate," Collins said in his opening remarks. "As I have told you on multiple occasions and proved at last week’s pharmaceuticals markup, I stand ready to work with you to promote solutions. I will not, though, become a bystander as you assail the attorney general and this committee. Our democracy deserves better."

Now that the Judiciary Committee has signed off on the contempt resolution, it will go to a vote in the full House. The timing of that vote would be up to House Speaker Nancy Pelosi, D-Calif.

Speaking at a Washington Post event Wednesday, Pelosi said that the attorney general "should be held in contempt," something she had declined to weigh in on as recently as Tuesday.

If the full House of Representatives votes to hold him in contempt, however, it might not result in any specific punishment. When Republicans controlled the House in 2012, they voted to hold President Barack Obama’s attorney general, Eric Holder, in contempt over the administration’s failure to turn over documents. In 2014, a federal judge declined the committee’s bid to hold Holder in contempt of court.

In a letter sent Tuesday night to Nadler after negotiations between committee lawyers and the Justice Department over accessing redacted portions of the report, Assistant Attorney General Stephen Boyd called the panel’s continued demands for materials “unreasonable” and urged them to delay Wednesday’s scheduled vote to initiate the contempt process.

“If the committee decides to proceed in spite of this request, however, the Attorney General will advise the President to make a protective assertion of executive privilege,” Boyd wrote.

Nadler responded sharply, calling the Justice Department’s continued obstruction of congressional oversight requests “dangerous.”

"The Department’s decision reflects President Trump’s blanket defiance of Congress’s constitutionally mandated duties," Nadler said in a statement. "In the coming days, I expect that Congress will have no choice but to confront the behavior of this lawless Administration.”

The Justice Department’s letter said that providing all the materials requested by Democrats would put ongoing investigations at risk, and in the case of grand jury material “force the Department to ignore existing law.” Assertion of privilege would be consistent with past administration practice.

Nadler disagreed. "This is, of course, not how executive privilege works,” he said in a statement late Tuesday. “The White House waived these privileges long ago, and the department seemed open to sharing these materials with us earlier today. The department’s legal arguments are without credibility, merit, or legal or factual basis.”

Nadler first issued a subpoena for Mueller's unredacted report and the underlying evidence April 19 and gave the department until last week to comply, and then set a new deadline of this past Monday to respond. Neither request was met.