WASHINGTON (AP) — The Justice Department has informed the House Judiciary Committee that Attorney General William Barr may skip a Thursday hearing on special counsel Robert Mueller’s report if committee lawyers seek to question him.

The Democratic-run committee plans to allow counsels from both sides to ask Barr about the Russia probe after the traditional round of questioning by lawmakers. Department officials also told the committee that they opposed a plan to go into a closed session if members wanted to discuss redacted portions of Mueller’s report, according to a senior Democratic aide on the committee, who spoke on condition of anonymity to discuss the confidential communications with the department.

Barr is scheduled to testify before the Senate Judiciary Committee on Wednesday and the House panel on Thursday. The GOP-led Senate committee is expected to have normal rounds of member questioning.

It is unusual for committee counsels to question a witness. But committees can generally make their own rules, and other panels have made similar exceptions. In a confirmation hearing for Supreme Court Justice Brett Kavanaugh last year, for example, Republicans on the Senate Judiciary Committee hired an outside prosecutor to question a witness who had accused Kavanaugh of sexual assault.

The dispute comes as tensions have escalated sharply between House Democrats and the Trump administration over full access Mueller’s report and government witnesses who have defied congressional subpoenas to testify. Democrats have been eagerly anticipating the hearing with Barr as they try to build on Mueller’s findings with their own investigations into the president.

House Democrats have subpoenaed the Justice Department for the unredacted version of the Mueller report and underlying material gathered from the investigation. In response, the Justice Department has said they will make the full report, minus grand jury material, available to a limited group of members — an offer that Democrats have so far refused. The dispute could eventually end up in court.

A spokeswoman for the top Republican on the committee, Rep. Doug Collins of Georgia, noted that Barr’s testimony is voluntary and criticized the Democrats for not reading the full report. “Democrats have yet to prove their demands are anything but abusive and illogical in light of the transparency and good faith the attorney general has shown our committee,” Jessica Andrews said.

House Judiciary Committee Chairman Jerrold Nadler, D-N.Y., has also invited Mueller to testify and subpoenaed former White House counsel Don McGahn. McGahn was a vital witness for Mueller in the report, which recounted the president’s outrage over the Mueller investigation and his efforts to curtail it. The White House has asserted it will fight the McGahn subpoena.

Associated Press writer Eric Tucker contributed to this report.