(CNN) —  

In his testimony to the Senate Judiciary Committee Wednesday, Attorney General William Barr was asked if the committee could see notes he took during a phone call with special counsel Robert Mueller.

“Did anyone, either you or anyone on your staff, memorialize your conversation with Robert Mueller?” Democratic Sen. Richard Blumenthal of Connecticut asked Barr, referencing a phone call between Barr and Mueller after the special counsel sent the attorney general a letter complaining about Barr’s summary of the Mueller report.

“There were notes taken of the call,” Barr conceded. When asked by Blumenthal if the committee could have the notes, Barr said “No.” When asked “Why not?” Barr simply said, “Why should you have them?”

So, does Congress have a right to the notes between Barr and Mueller?

Facts first: In theory, Congress could get access to these notes, but it would likely take a subpoena, a possible criminal contempt citation, and years of court battles.

This all comes as Congress contemplates how to deal with the Justice Department’s denial of House Democrats’ request to hand over an unredacted version of the Mueller report, and whether to hold the attorney general in contempt over his refusal to appear before the House Judiciary Committee.

Given Barr’s answer Wednesday, alongside the administration’s lack of compliance with other congressional subpoenas, it’s unlikely that Barr would willingly give Congress his notes on his conversation with Mueller.

The next step for Congress would likely be issuing a subpoena. Each committee has their own rules on subpoenas, who can submit them and how. When it comes to the Senate Judiciary Committee, that power resides with chairman Lindsey Graham, Republican of South Carolina, who is unlikely to subpoena Barr for anything.

That leaves any subpoena up to chairman of the House Judiciary Committee, New York Democratic Rep. Jerry Nadler.

In refusing Nadler’s potential subpoena, Barr could cite the Office of Legal Counsel rules protecting communications that are related to litigation or to internal deliberative matters. In that event, Nadler could try to hold Barr in contempt. Doing so would likely trigger a lengthy legal process that could take years to resolve.

To understand the process, CNN’s Facts First spoke to Morton Rosenberg, a congressional scholar at the Project on Government Oversight, and senior fellow at Good Government Now. Rosenberg spent 35 years as a senior legal analyst at the Congressional Research Service and has written extensively about congressional investigation and oversight powers.

Rosenberg says the quickest way for House Democrats to compel Barr to hand over his notes would be to issue a criminal contempt citation against him.

For that to happen, there would first need to be a vote in the committee which, if successful, would lead to a debate on the House floor and ultimately a vote, according to Rosenberg. If the vote were to pass, a criminal contempt citation would then be drafted and sent by Speaker of the House Nancy Pelosi to the US attorney for the District of Columbia.

It’s up to the US attorney to submit this citation to a grand jury. If a judge actually ruled that Barr was in criminal contempt of Congress, he could be sent to jail. The catch, however, is that the attorney general oversees that US attorney; so Barr could simply direct the US attorney not to submit the criminal contempt citation, which has happened in the past.

In that case, Congress would have to rely on a civil contempt citation (rather than a criminal citation), which is far less powerful and would likely take much longer to enforce. “A civil contempt citation won’t get an answer before the 2020 election,” said Rosenberg.

There is recent precedent for Congress to compel an attorney general to release documents through criminal contempt. During the Obama administration, House Republicans attempted to hold then-Attorney General Eric Holder in criminal contempt for refusing to supply Congress with certain documents relating to the Fast and Furious gun-running sting.

But the Justice Department under Holder refused to submit the criminal contempt citation to a grand jury, said Rosenberg, leaving House Republicans to rely on civil contempt charges against Holder, which have proved much more arduous.

“The problem is it takes so much time,” Rosenberg told CNN. “Fast and furious is still going on. So by the time these things get resolved, they are irrelevant, at least to the political climate.”