Comey said that the White House's characterizations of the FBI under him were "lies, plain and simple."
Fired FBI honcho James Comey has come out swinging as he told a Senate intelligence committee that he was shocked and unnerved when President Trump "chose to defame me" following his ouster.
Comey said that in conversations with Trump both before and after he had moved into the White House, he was repeatedly told he had been doing a great job as FBI director, so his dismissal came as a surprise.
Read: After Trump Tweets About Terror Attack, London Mayor Wants President's Visit Canceled
Addressing the president's assertions that the FBI was in disarray under him, Comey said Trump's remarks were “lies, plain and simple.”
“Although the law requires no reason at all to fire an FBI director, the administration then chose to defame me and more importantly the FBI by saying that the organization was if disarray, that it was poorly led, that the work force had lost confidence in its leader.
“Those were lies plain and simple. And I am so sorry that the FBI work force had to hear them and I am so sorry that the American people were told them,” he said.
Comey told lawmakers that he had "no doubt" that the Russian government tampered with the 2016 presidential election.
Comey was asked by Senator Richard Burr when he became aware of Russia’s election cyberattacks and said it came in the “late summer of 2015,” which would have been months after Trump jumped into the race.
He was also asked if President Trump tried to stop the Russia investigation, and Comey replied: “not to my understanding, no.”
Later in the questioning, Comey said: "There should be no fuzz on this. The Russians interfered with our election… They did it with purpose. They did it with sophistication. It’s not a close call. It happened.”
Comey was fired on May 7. At the time, he meeting with the L.A. bureau of the FBI, and learned the news on television. He later returned home to the East Coast as a civilian.
Read: Trump Slams London Mayor After Terror Attack and Shuns 'Political Correctness'
“I want the American people to know this truth — the FBI is honest, the FBI is strong, and the FBI is and always will be independent,” he said during his testimony.
After he was sworn in, Comey said he would not read his opening statement submitted Wednesday, but addressed his former FBI staff when he said he was sorry he was unable to say goodbye.
During an impassioned speech before questioning, Comey said: “I worked every day at the FBI to help make that great organization better. The FBI will be fine without me."
Watch: Is Trump Recording Oval Office Visitors? Speculation Grows as Impeachment Talk Swirls