Democrats have demanded that Whitaker step back from Mueller's continuing investigation because he openly criticized the probe in interviews past year before he joined the Justice Department.
"That takes the transparency of the report out of the special counsel process in the hands of the attorney general, and moves it over to White House counsel", Whitehouse said.
At the same time, two Judiciary panel members - Republican Chuck Grassley and Democrat Richard Blumenthal - said Monday that they're proposing legislation that would require Mueller's report to be made available to the public and Congress when the investigation is complete.
Whitaker didn't say exactly when he thought the investigation would end.
The Senate Judiciary Committee had been planning to vote on whether to approve his nomination this morning.
"As I testified, I believe that Robert Mueller should be allowed to finish his investigation".
"I hope that we can get the report from Director Mueller as soon as possible", he said.
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.
Senator Graham Says Trump Discussed Using US Military Force in Venezuela
Venezuela's Foreign Ministry says it has extended a deadline for USA diplomats to leave following it's rupture in relations. This is the US supporting the people of Venezuela, who want their constitution and democracy followed.
Barr, who served as Attorney General from 1991-1993 under President George H.W. Bush, said in his confirmation hearing before the Judiciary Committee on January 15 that he sent the memo "as a former attorney general who has often weighed in on legal issues of public importance".
It is unknown if Mueller is planning additional indictments after charges were filed against Roger Stone, but the Special Counsel's investigation has been known for keeping information under wraps, preferring to speak through court filings. He also pledged to ask Barr whether he would let Trump claim executive privilege to muzzle portions of the report.
The Justice Department's regulations call for the special counsel to give the attorney general a "confidential" report when he completes his work, but nothing compels whoever is acting as attorney general for the purposes of the regulation - whether Rosenstein, Whitaker or Barr - to release it to anyone. If the special counsel were fired or resigned, a public report would have to be released in two weeks.
Although Barr appears on track to be confirmed, Democrats want a guarantee that whatever Mueller writes will be public.
The delay, which is not unusual, is not expected to affect Barr's confirmation, the Washington Post reported Tuesday.
"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.
Trump has slammed the Russian Federation investigation as a "witch hunt" and says there was no collusion.