Comey, however, stuck by his decision to notify Congress of new emails related to the Clinton email probe less than two weeks before Election Day.
"It makes me mildly nauseous to think we had some kind of impact on this election", he said. Yates is expected to tell a Senate Judiciary subcommittee led by Sen.
FBI Director James Comey beat back questions about the continuing federal probe into Russian interference in the U.S. elections, as senators tried to pry any bit of information out of him Wednesday.
Speaking on Capitol Hill today, Comey said that if he could revisit his actions from the fall, he would have made the same decisions.
He told the panel one reason for the FBI's renewed interest in Clinton's case was that investigators had found emails, some of them classified, forwarded by Clinton's assistant Huma Abedin to her husband, who was not authorized to see such information.
Mr Comey said he stands behind his letter to Congress that shook up the final days of last year's presidential election and he would do it again.
"When the Anthony Weiner thing landed on me on October 27 and there was a huge - this is what people forget - new step to be taken, we may be finding the golden missing emails that would change this case, if I were not to speak about that, it would be a disastrous, catastrophic concealment", he said.
Mr Comey's announcement of a fresh investigation on October 28th and the WikiLeaks controversy "raised doubts in minds of people who were inclined to vote for me but got scared off", Mrs Clinton said in an interview in NY on Tuesday.
Late Tuesday evening Trump posted tweets saying, among other things, "FBI Director Comey was the best thing that ever happened to Hillary Clinton in that he gave her a free pass for many bad deeds!"
"I'm a Patriots fan, and I think if games ended in the third quarter, there would have been a different team here [at the White House]", he said.
Customer fatally shoots man who killed sports bar manager
Two people were killed and a third was injured after a shooting at an Arlington sports bar Wednesday evening, police say. There were about 20 people in the bar at the time, and they were being interviewed by detectives.
Comey said he felt he had to inform Congress at the time, after which news of the reopened probe was leaked to the press, because he had previously testified under oath that the investigation had been closed.
Against the backdrop of that decision, and in recognition of the extraordinary public interest in the Russian Federation investigation, there will nearly certainly be a mechanism for providing to the public details of the government's findings - even if a full, and more extensive, report remains classified, Fallon said.
Comey has yet to speak publicly about the details of the investigation into President Donald Trump's campaign's alleged ties to Russian Federation prior to the election.
Comey said he welcomed the review.
USA intelligence agencies in December accused Russian-backed hackers of interfering in the election to tarnish Clinton and the Democratic Party in a bid boost Trump's chances of victory.
Wednesday's public hearing marked the second time Trump knocked his own Federal Bureau of Investigation director around the time of his public hearing.
For Comey, Lynch's meeting with Bill Clinton was the last straw.
While warning that "no agreement can be imposed by the United States or any other nation", he said he would "love to be a mediator arbitrator, or facilitator for the peace process".
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