House Judiciary Committee Chairman Jerry Nadler (D-NY) on Monday threatened to subpoena Attorney General William Barr if he does not appear before the committee on Thursday to testify on the Special Counsel report.

“We’ll have to use whatever means we can to force a subpoena,” Nadler said, according to CNN.

Barr is scheduled to testify to the Senate Judiciary Committee on Wednesday and the House Judiciary Committee on Thursday but may skip the House hearing, reportedly over his opposition to the hearing’s format.

Nadler has said he wants each member to have five minutes to question Barr each, and then allow staff for each side to have half an hour to question him. Nadler called that a “standard method of doing things,” but added that “sometimes it’s used, sometimes it’s not.”

“It’s in my judgment an effective way of doing things, and the witness is not going to tell the committee how to conduct its hearing. Period,” he said.

Nadler reportedly wants Barr to stay for a closed-door second round of questions, to discuss redacted material from the report, which Barr also opposes.

Department of Justice spokeswoman Kerri Kupec told The Hill that “members of Congress should be the ones doing the questioning.”

“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,” Kupec said.

Breitbart News reached out to the Justice Department on Monday afternoon but did not get an immediate response.

Democrats have accused Barr of playing politics when he cleared the president of obstruction of justice.

Special Counsel Robert Mueller and his team did not establish any collusion between the Trump campaign and Russia during the 2016 election, yet did not make a determination on obstruction of justice. Barr said they left the decision up to him, since it is the Justice Department’s role to prosecute.

Democrats claim that Mueller intended to leave the decision to prosecute the president on obstruction up them, even thought legal experts disagree. Former Attorney General Michael Mukasey said in a recent interview with CNN that it was not up to Congress to decide whether to prosecute someone.

“The Justice Department doesn’t conduct investigations for the purpose of referring things to Congress,” Mukasey, also a former judge, told CNN’s Chris Cuomo last week. “They conduct criminal investigations with two possible results. Either you charge or you don’t charge.”

Mukasey said Congress only decides “whether to impeach or not,” but not whether to charge someone.

“Congress doesn’t indict. Congress can impeach,” he said.