Feinstein - against the wishes of Senate Judiciary Committee Chairman Chuck Grassley (R-IA) - on Tuesday morning released the full transcript of an interview in August with Glenn Simpson, the co-founder of Fusion GPS, the firm hired by the Hillary Clinton campaign and the Democratic National Committee to dig up dirt on Trump's ties with Russian Federation.
President Donald Trump slammed Senate Judiciary ranking member Dianne Feinstein for releasing the transcript of Fusion GPS leaders' testimony to the panel, calling her "sneaky" and suggesting - without evidence - she might have broken the law.
He went on to call for Feinstein to face a "tough" primary challenge in her 2018 reelection campaign.
She released the transcript of Glenn Simpson's interview against the objections of the committee's Republican chairman Chuck Grassley.
Defending the release of the transcript on Tuesday, Feinstein said it was necessary in order to combat false information circulating about the Simpson interview.
President Donald Trump said Wednesday that it "seems unlikely" that he'd give an interview in special counsel Robert Mueller's investigation into potential coordination between Russian Federation and the Trump campaign.
Last week, two Republican senators, Chuck Grassley and Lindsey Graham, wrote to the Department of Justice, demanding that a criminal prosecution be undertaken to target Steele for allegedly lying to FBI investigators.
Lindsey Graham, R-S.C., referred Christopher Steele, the former British intelligence officer who compiled a dossier with allegations concerning President Trump and Russian Federation, to the Justice Department for investigation.
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Michael Cohen also filed a second lawsuit against Washington research firm Fusion GPS, the company that hired former spy Christopher Steele to investigate Mr Trump's business dealings with Russian Federation.
In urging the committee to release the full transcript of his interview, Simpson has argued that Republicans are trying to obscure what happened in 2016.
"It's totally confounding", said a Grassley spokesman, Taylor Foy.
"Listen, I screw up regularly and she doesn't owe me an apology", Grassley said.
He faulted the company for recklessly distributing the dossier and allowing it to "fall into the hands of media devoted to breaking news on the hottest subject of the day: the Trump candidacy". "By then it was obvious there was a crime in progress", Simpson said.
Several Republican-led committees are now probing whether the document formed the basis for the FBI's initial investigation into alleged Russian meddling in the 2016 presidential race.
Feinstein is the top Democrat on the committee. "And I don't make an excuse but I've had a bad cold and maybe that slowed down my mental facilities a little bit", she said, according to a tweet from a fellow NBC producer.
He said that seems much more likely than the report that a former Trump campaign adviser's drunken boasts - not the dossier - led to the investigation.