House Judiciary Chairman Jerry Nadler (D-N.Y.) has scheduled a committee vote on Wednesday to allow staff lawyers to question Attorney General Bill Barr during his hearing this week.

Why it matters: Barr has threatened to cancel his appearance before the panel on Thursday over the proposed format, with the Justice Department arguing that Barr had agreed to appear before Congress — and therefore "members of Congress should be the ones doing the questioning." Nadler, who has pledged to subpoena Barr if he doesn't show up, told reporters Monday: "It’s not the business of a witness to try to dictate to a congressional committee what our procedures for questioning him are."

The big picture: Thursday's hearing will be the first opportunity for Democrats to question Barr since the release of the redacted Mueller report, after many accused the attorney general of spinning the special counsel's findings on behalf of President Trump.

It's likely to be the first of many Democrat-led interrogations of Trump administration officials in the post-Mueller world, though the White House has made clear that it will not voluntarily comply with any of the House's investigations or subpoenas.

As the top law enforcement official in the country, however, it remains to be seen whether Barr will stonewall Congress to the same level as more openly partisan Trump officials. Public pressure for Barr to explain why he chose to exonerate Trump on obstruction of justice — a move that seemingly downplayed the breadth of evidence of obstruction presented in the Mueller report — could force his hand.

What to watch: The hearing on Thursday will be preceded by Barr's appearance before the Republican-controlled Senate Judiciary Committee on Wednesday, expected to be a less hostile environment chaired by Trump ally Lindsey Graham.

Graham, who played a significant role in President Bill Clinton's impeachment proceedings, has blasted Democrats as "political hacks" and said he doesn't care about the evidence of obstruction that Mueller laid out: "From my point of view, I've heard all I need to really know. Now I want to look and find out how all this happened."

2020 presidential candidates Sens. Kamala Harris, Amy Klobuchar and Cory Booker will be among the Judiciary Democrats to question Barr.

Go deeper: How Trump can stall House Democrats' investigations and subpoenas