Mr Mueller faces court deadlines in two pivotal cases on Friday, and ex-FBI Director James Comey is set to appear before politicians on Capitol Hill.
Comey was in charge of both those investigations.
"He wanted a public spectacle and he really wanted five minutes back and forth with members taking shots", Rep. Darrell Issa (R-CA) explained on Fox News during a break from the questioning, which was expected to go until 4:15 p.m. ET. "But I'm trying to respect the institution and answer questions in a respectful way", he said after the hearing, adding in a tweet: "In the long run, it'll make no difference because facts are stubborn things". They argued that a closed hearing was 'abusive to witnesses'. "We should be talking about the Russian Federation investigation [instead], and quite frankly obstruction of justice".
The details of the transcript revealed that Comey left lawmakers frustrated with his lack of specifics. She used a private email server to conduct official diplomatic business while she was secretary of state. This is a term that he began using shortly after Democrats reclaimed the House of Representatives in November. Republicans were able to hold onto their majority in the Senate.
"It's a waste of time to start with", Rep. "The entire goal of this investigation is to cast aspersions on the real investigation ... there is no evidence whatsoever of bias at the FBI or any of this other nonsense". "There is no evidence whatsoever of bias at the Federal Bureau of Investigation or any of this other nonsense".
President Donald Trump, speaking behind a microphone during a press conference at the White House. He has since become a vocal critic of the president and has periodically opined on the ongoing investigation against him.
The FBI's counterintelligence investigation into potential ties between the Trump campaign and Russia initially focused on four Americans and whether they were connected to Russian efforts to interfere in the 2016 presidential election.
Comey told reporters after the hearing he had total confidence that the use of electronic surveillance as part of investigation was handled in a "thoughtful, responsible way" by the Department of Justice and the FBI.
Comey appeared for the interview after unsuccessfully fighting a subpoena in court.
It doesn't seem to be going as planned. The panel, per his request, will release a transcript of the interview to the public, and he can explain his answers for himself. He said that move was in the name of their combined desire for transparency.
A report released this June from the Justice Department's internal watchdog said Comey was "insubordinate" in his handling of the Clinton email investigation in the final months of the 2016 campaign.