Democrats continue extended talks with Mueller, DOJ over special counsel's testimony

House Democrats have waited for weeks to hear from special counsel Robert Mueller since the release of his report - and they're going to have to keep waiting.

On Friday, House Judiciary Committee Chairman Rep. Jerry Nadler, D-N.Y., told ABC News it was unlikely that Mueller would appear before his panel by the end of next week, when the House wraps up its legislative business for the month ahead of the week-long Memorial Day recess.

Initially, the committee had hoped to hear from Mueller this past Wednesday, May 15, but that tentative hearing date came and went without an agreement.

The special counsel's office did not immediately respond to a request for comment on the discussions with the House Judiciary Committee.

Ongoing discussions between Democrats, the special counsel's office and the Justice Department are centered on the timing, nature and scope of Mueller's testimony, according to people familiar with the discussions.

The White House's recent assertion of executive privilege over the entire report and underlying materials also looms over negotiations, and could impact Mueller's potential testimony.

While Attorney General Bill Barr has said he has no objections to Mueller testifying -- most recently in an interview with the Wall Street Journal this week - Democrats have accused the Justice Department of slow-walking the discussions.

One complicating factor in the negotiations, according to people familiar with the talks, is Mueller's unwillingness to enter the political fray over his findings.

President Donald Trump's initial objection to Mueller testifying stalled discussions at first, as the special counsel sought clarification on the White House's position on his appearance. But Trump has since said that he would let Barr decide whether Mueller would appear.

The House Intelligence Committee, led by Democratic chairman Rep. Adam Schiff, D-Calif., is also working to schedule a subsequent hearing with Mueller that could include public and closed-door classified sessions.

"I feel very confident saying Mueller's going to testify," Schiff told ABC News. "There's no way that he cannot, and the public won't stand for it. I think the Justice Department knows they're on the poorest of ground in trying to prevent his testimony."

The talks have also taken place as Democrats and the Justice Department spar over access to the Mueller report and the special counsel's underlying materials. The department has not complied with subpoenas from both panels interested in hearing from Mueller, which could prompt Democrats to hold Barr in contempt of Congress.

Democrats could eventually seek to compel Mueller's testimony with a subpoena, but are hoping to avoid doing to bring the special counsel to Capitol Hill voluntarily.

The special counsel found no evidence of coordination between Trump and his campaign and the Kremlin to influence the 2016 presidential election. While his report examined a number of episodes of potential obstruction of justice, Mueller did not make a determination on whether Trump obstructed justice.

Some Democrats have said Mueller's testimony is essential to help clarify elements of his report - both for the country, and for lawmakers contemplating potential impeachment proceedings over his conclusions.

"He needs to be pressed on the issue of obstruction," Rep. Brian Higgins, D-N.Y., told ABC News. "Mueller didn't do us any good and I think a lot more pressure should be brought to bear on him for being I think deliberately opaque."

While they wait to hear from Mueller, Democrats are battling with the administration over information and documents, including President Trump's tax returns and the full Mueller report, in more than a dozen investigations - with many of the fights expected to head to court.

Without Mueller, Democrats are left with few tools to try and tell the story of his findings, and are resorting to other strategies: On Thursday, more than two-dozen Democrats spent 12 hours reading Mueller's public report aloud in a Capitol hearing room, in an effort to draw attention to the report.