The Senate Judiciary Committee on Tuesday postponed a vote on attorney general nominee William Barr by one week after Democrats raised concerns about how Barr will handle special counsel Robert Mueller's report once he completes his investigation into Russian interference in the 2016 election.

Those concerns became more pressing after Acting Attorney General Matt Whitaker told reporters on Monday that the Mueller investigation was "close to being completed" and that he hopes that a report will be produced by Mueller "as soon as possible."

Barr has repeatedly pledged as much transparency as possible in how he will handle Mueller’s investigation. But at a committee business meeting Tuesday, Sen. Dianne Feinstein of California, the ranking Democrat, raised questions about Barr's pledge, calling it "qualified."

Sen Sheldon Whitehouse, a Rhode Island Democrat, put a sharper point on his concerns. "We’re both lawyers and we know that there are weasel words that can be put into sentences and the question of what transparency is consistent with the law is a ginormous loophole in his transparency pledge."

And newly released written responses to senators’ questions show how Justice Department regulations could keep some of the special counsel’s findings cloaked in secrecy.

Democrats pressed Barr for written, on the record, answers about what he’ll be willing to share about the probe with Congress and the public. With the investigation now nearing completion, Barr’s answers take on even greater significance.

Barr left open the possibility that he could object to efforts to bring Mueller up to testify before congressional committees. Barr isn’t promising to allow the special counsel to testify before Congress if invited or subpoenaed. In his written responses to senators’ questions, Barr would only say that he would consult with Mueller and “other [Justice] Department officials about the appropriate response to such a request in light of the Special Counsel’s findings and determinations at that time.”

Mueller is required to submit a “confidential” report to the attorney general upon completion of his investigation. What gets released to the public will be almost entirely up to Barr to decide, should he be confirmed. Barr testified during his confirmation hearing that he believes “it is very important that the public and Congress be informed of the results of the special counsel’s work.” He added that he would “follow the special counsel regulations scrupulously” and that his goal “will be to provide as much transparency as I can consistent with the law.”

Those regulations could potentially keep information about uncharged individuals, namely President Trump, from ever reaching Congress or the public.

In written questions, Whitehouse pressed Barr on whether Justice Department regulations would be applied to the Mueller report. In his response, Barr acknowledged that regulations allow the attorney general to publicly release his report “to the extent that release would comply with legal restrictions.” But Barr added that it is “Department policy and practice not to criticize individuals for conduct that does not warrant prosecution.”

Barr went on to explain that the Office of Legal Counsel (OLC)opinion that it would be unconstitutional to indict or prosecute a sitting president remains operative.

With no charge permitted against the president, Barr seems to indicate that any release of information about Trump from the investigation might be limited.

“If the only reason he is an uncharged person is because OLC’s internal, untested, never signed off on by any judge, policy makes him an uncharged person, we gotta to get to the bottom of that,” Whitehouse said.

Judiciary Chairman GOP Sen. Lindsey Graham acknowledged that Whitehouse had raised a "good question to get an answer to."

"We'll give him a call," Graham added.

During his confirmation hearing, Barr was critical of how former FBI Director James Comey handled the conclusion of the Hillary Clinton email investigation. “If you are not going to indict someone, then you do not stand up there an unload negative information about the person,” Barr testified. “That is not the way the Department of Justice does business.”

Congressional committees have opened numerous investigations into the Trump administration. But Barr says the Justice Department is under no obligation to help Congress conduct those investigations as they relate to people who have not been charged.

“Congress can and does conduct its own investigations, and its right to do so is not precluded by the Department’s decision not to provide certain information about an uncharged individual gathered during the course of a criminal investigation,” Barr writes.

At Tuesday's hearing, Feinstein said that Barr's indication that he would write a separate report that he would provide to Congress instead of Mueller's report is something "that needs to be fleshed out."

"This is the biggest issue facing our country and the American people deserve to know Mueller’s findings and analysis without any filter," Feinstein added.

Regulations that require Mueller to provide a confidential report to the attorney general "do not prohibit him from sharing this report to Congress," she said.

While Barr’s written responses track closely with his hearing testimony, questions about what the public will be able to see at the conclusion of the special counsel’s investigation remain.