Attorney General William Barr threatened to bail on a scheduled Thursday hearing of the House Judiciary Committee to review special counsel Robert Mueller’s Russia report if the panel moves forward with its proposed questioning format, two senior Democratic committee aides confirmed to HuffPost.

The Justice Department allegedly took issue with the panel’s plan to allow committee counsels for each political party to ask Barr follow-up questions for 30 minutes each following the traditional round of questioning by its members. CNN and The Associated Press first reported the dispute.

Justice officials also reportedly pushed back on the committee’s plan to go into a closed-door session if members want to discuss redacted portions of Mueller’s report, which summarized the special counsel’s investigation into Russian interference in the 2016 election and whether President Donald Trump obstructed justice.

“The executive session is a right we always preserve if there are questions that need to be asked in a secure setting,” one of the aides told HuffPost. “It is not a guarantee that we would go into executive session, only if the answers from Barr need a secure setting to be given.”

The Justice Department said in a statement to CNN that Barr had agreed to appear before Congress and therefore only members of Congress should be allowed to question him during the hearing.

“He remains happy to engage with members on their questions,” according to the department’s statement.

It’s unclear why Barr allegedly opposes a closed-door session. The Justice Department did not immediately respond to HuffPost’s request for comment.

It’s unusual, though not unprecedented, for committee counsels to question a witness, the AP reported, noting that Senate Judiciary Committee Republicans hired an outside lawyer to question Christine Blasey Ford during Brett Kavanaugh’s Supreme Court confirmation hearing last year.

Barr is scheduled to testify before the Senate Judiciary Committee on Wednesday. The Republican-led Senate panel is expected to subject Barr to a traditional round of questioning by its members.

Sen. Lindsey Graham (R-S.C.), chairman of the Senate Judiciary Committee, said he’s “heard all I need to know” about the Mueller report and wants to dig deeper into the origins of the special counsel’s investigation.

“I think the idea that this president obstructed justice is absurd,” Graham told CBS’ “Face the Nation” on Sunday. “I can’t think of one thing that President Trump did to stop Mueller from doing his job.”