Democrats made moves Monday in defiance of Attorney General William Barr's wishes ahead of his planned testimony before the House Judiciary Committee this week.

The two sides are grappling over the terms of the top Justice Department official's testimony on special counsel Robert Mueller's report, and if they can't reach an agreement, a subpoena could be in the making.

Barr is scheduled to testify before the committee Thursday but threatened to pull out this week after getting word that Judiciary Chairman Jerry Nadler, D-N.Y., wants to add additional rounds of questions where the counsel for the Democratic and Republican parties would have 30 minutes to ask Barr questions. The Justice Department has so far not signaled a willingness to accept those terms.

“The Attorney General agreed to appear before Congress. Therefore, Members of Congress should be the ones doing the questioning. He remains happy to engage with Members on their questions regarding the Mueller report," a Justice Department spokesperson told the Washington Examiner early Monday morning.

Undaunted by the DOJ's objections, the Democratic majority formally announced on Monday it would stick to Nadler's preferred format, counsel questioning included. Rep. Jamie Raskin, D-Md., a member of the House Judiciary Committee, told Politico that he believes Barr is trying to exert undue control over the committee.

“The attorney general seems to want to dictate the internal decision-making of the House Judiciary Committee. That’s plainly unacceptable to us,” Raskin said. “We obviously can’t and don’t tell him how to run his meetings. And he can’t tell us how to run our meetings.”

Nadler suggested Barr might be afraid but strongly hinted that a subpoena would ensue if the attorney general doesn't show.

"If the attorney general is afraid to subject [himself] to questions where you can follow up, that may indicate lack of confidence in his own position," Nadler said to reporters Monday. "And more to the point, we have to get to the bottom of these issues. That's why we've called him in. It's not up to the attorney general to tell the committee how to conduct its business."

The White House has said it prefers cooperation with lawmakers, but press secretary Sarah Sanders snapped at Democrats on Monday. “You have to look at the outrageous behavior, particularly of the House Democrats, who are asking for things they know they can't have, that they know they have no legal authority to have,” Sanders said.

Barr is also set to testify before the Republican-controlled Senate Judiciary Committee on Wednesday, which by all appearances is still a go.

A redacted version of Mueller’s report on his 22-month investigation was released on April 18. The report clears Trump of colluding with Russia but also lays out 10 instances where Trump might have obstructed justice. Attorney General William Barr and former Deputy Attorney General Rod Rosenstein wrote a four-page summary of Mueller’s investigation last month that cleared Trump of conspiring with Russia and of obstructing justice.

Upset with Barr’s rollout and emboldened by some of the findings in Mueller’s report, Democrats have ratcheted up calls for investigations into the president and his administration, although leadership has sidestepped calling for impeachment proceedings.

Jerry Dunleavy contributed to this report.