Attorney General William Barr has threatened he may not show up to his scheduled testimony before the House Judiciary Committee about special counsel Robert Mueller’s report on Thursday as his office has made it clear to Democrats that he is none too happy with the format of the hearing. CNN was first to report the story, which was later confirmed by several others, citing an unnamed committee source that said Barr wouldn’t go to the hearing unless there was a change in the proposed format. Failing to attend the hearing would mark a huge escalation in tensions between the Trump administration and Democrats, who have requested to see the full, unredacted Mueller report.

There are two basic sticking points. First, House Judiciary Chairman Jerry Nadler has proposed that after lawmakers complete their allotted time for questioning there would be an additional 30-minute round for each side of the aisle in which Democratic and Republican counsels could question Barr. “The attorney general agreed to appear before Congress. Therefore, members of Congress should be the ones doing the questioning,” Justice Department spokeswoman Kerri Kupec said. “He remains happy to engage with members on their questions regarding the Mueller report.” Barr is also reportedly opposed to the idea of moving to a closed session if lawmakers want to discuss parts of special counsel Robert Mueller’s report that were redacted.

Nadler was defiant Sunday morning, telling CNN that Barr would not “dictate the format of the Judiciary Committee.” Nadler added that “the witness is not going to tell the committee how to conduct its hearing, period.” Asked what could be the next step if Barr doesn’t agree to testify, Nadler didn’t mince words. “Then we will have to subpoena him, and we will have to use whatever means we can to enforce the subpoena,” he said.

Barr is scheduled to testify before the Senate Judiciary Committee on Wednesday and the House committee on Thursday. Seeing as though the hearing is still a few days away, the two sides could still come up with some sort of compromise that would allow it to move forward as scheduled.