The Justice Department tapped former FBI director Robert Mueller to be a special counsel overseeing the Russia investigation, the department announced Wednesday.

The news comes as President Trump and his administration grapple with the fallout from explosive revelations earlier this week that now-fired FBI director James Comey kept notes of a February meeting indicating Trump asked him to close the agency's investigation into former National Security Adviser Michael Flynn.

The memo, on the heels of Trump's abrupt firing of Comey last week, fueled accusations by lawmakers of possible obstruction of justice and calls for an independent prosecutor to oversee the FBI's ongoing counterintelligence probe into possible collusion between Trump campaign associates and Russia during the presidential campaign.

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Mueller served as FBI director from 2001 to 2013 under both the George W. Bush and Obama administrations.

Key Republicans lawmakers immediately welcomed the announcement. "Mueller is a great selection. Impeccable credentials. Should be widely accepted," tweeted Rep. Jason Chaffetz, R-Utah, chair of the powerful House Oversight and Government Reform committee.

Democratic senators welcomed the news. Sen. Richard Blumenthal, D-Conn., tweeted that Mueller "has the experience and expertise, guts and backbone necessary to uncover and hold wrongdoers accountable." Sen. Martin Heinrich, D-N.M. said in a tweet that the appointment of a special counsel is "a step in the right direction."

Mueller, who preceded Comey as FBI director, was the longest serving director since J. Edgar Hoover. He served two additional years beyond his 10-year term, to ensure stability during a transition period in President Obama's national security team.

His appointment in the Russia investigation, the Justice Department said Wednesday, was made through the special counsel statute. It was exercised only once before, in 1999, when then-Attorney General appointed Former Missouri Sen Jack Danforth investigation into FBI handling of government raid on Branch Davidian compound at Waco, Texas.

Mueller will resign from his private firm to avoid any conflicts of interest with firm clients or attorneys, the Justice Department said.

In his special counsel role, Mueller assumes all the powers of a federal prosecutor – including subpoena authority.

"I have determined that a special counsel is necessary in order for the American people to have full confidence in the outcome," Rosenstein said. "Our nation is grounded on the rule of law and the public must be assured that government officials administer the law fairly. Special Counsel Mueller will have all appropriate resources to conduct a thorough and complete investigation, and I am confident that he will follow the facts, apply the law and reach a just result."

The authority to appoint a special counsel fell to Rosenstein after Attorney General Jeff Sessions recused himself from the Russia case because of his pre-election contacts with Russian ambassador Sergey Kislyak, which Sessions did not disclose during his Senate confirmation hearing.

Under provisions of the special counsel statute, Rosenstein still maintains some oversight authority in the investigation. But any decision to overrule the appointed counsel requires notification to the chairs of the House and Senate Judiciary committees.

The White House offered no immediate comment. Administration officials there could be seen racing in and out of West Wing offices, formulating a response to the new development.

White House officials such press secretary Sean Spicer had said as recently as Tuesday there was no need for a special counsel.

Not all lawmakers saw the need for a special counsel. "I think probably the hysteria was building up and they figured they'd calm it down send some raw meat to the wolf pack," Rep. Peter King, R- N.Y., former Homeland Security Committee chairman, told reporters about the reasoning for selecting one. "If there's gonna be one there's gonna be one, doesn't matter to me but I don't see a need for it."

Meanwhile, some Democrats indicated Mueller's appointment might not be enough. "I respected him as FBI director. I think he did a great job," said Rep. Jim Clyburn, D-S.C. "I think people are beginning to understand that this is bigger than Trump – this is about the country."

Still, he said he hoped Congress would appoint a separate panel to take on the Russia inquiry. "To me this does not negate a 9/11-type commission," Clyburn said.

The intelligence community has accused Moscow of orchestrating a campaign of cyberattacks against Democratic political organizations during the elections, and leaking them to websites such as WikiLeaks with the goal of undermining Hillary Clinton's campaign and public confidence in the democratic process.

Contributing: David Jackson, Jessica Estepa, Eliza Collins, Erin Kelly

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