Getty Images
Now playing
03:17
Voicemail from Trump's attorney to Flynn's lawyer released
Ktyrsten Sinema/Mark kelly split
Getty Images
Ktyrsten Sinema/Mark kelly split
Now playing
02:55
Biden's top priorities depend on support from these two senators
Getty/CNN
Now playing
01:57
'Do you know how crazy this is?': Tapper on Arizona election 'audit'
Caitlyn Jenner attends the 28th Annual Elton John AIDS Foundation Academy Awards Viewing Party on February 9, 2020 in West hollywood, California. (Photo by Michael Tran / AFP) (Photo by MICHAEL TRAN/AFP via Getty Images)
Michael Tran/AFP/Getty Images
Caitlyn Jenner attends the 28th Annual Elton John AIDS Foundation Academy Awards Viewing Party on February 9, 2020 in West hollywood, California. (Photo by Michael Tran / AFP) (Photo by MICHAEL TRAN/AFP via Getty Images)
Now playing
02:41
Caitlyn Jenner says friends are fleeing California because of homeless people
Anthony Blinken BBC intv
BBC
Anthony Blinken BBC intv
Now playing
03:27
Blinken: US will respond if Russia acts recklessly against Ukraine
02 Gen. David Petraeus lead 05062021
CNN
02 Gen. David Petraeus lead 05062021
Now playing
02:14
Gen. Petraeus on why US may regret pulling troops from Afghanistan
The Ohio Channel
Now playing
01:00
State senator attends Zoom meeting while driving his car
Florida Gov. Ron Desantis holds up the voting bill after signing it on Fox News live. The cable news network was the only press outlet granted access to the signing.
Fox News
Florida Gov. Ron Desantis holds up the voting bill after signing it on Fox News live. The cable news network was the only press outlet granted access to the signing.
Now playing
03:42
Florida governor goes on Fox News to sign controversial law
pool
Now playing
01:28
'Pay your fair share': Biden pitches raising taxes on wealthy
Now playing
03:46
Berman: McCarthy sides with these Republicans but not Liz Cheney?
CNN
Now playing
04:22
'Power and money over ethics': Avlon fires off on GOP
Kevin McCarthy, R-Calif., and Liz Cheney, R-Wyo., conduct a news conference in the Capitol Visitor Center after a meeting with the House Republican Conference on Wednesday, September 23, 2020.
Tom Williams/CQ-Roll Call/Getty Images
Kevin McCarthy, R-Calif., and Liz Cheney, R-Wyo., conduct a news conference in the Capitol Visitor Center after a meeting with the House Republican Conference on Wednesday, September 23, 2020.
Now playing
02:55
Hear McCarthy on a hot mic revealing what he thinks of Cheney
CNN
Now playing
03:08
'Dumb, stupid tribalism': CNN commentator slams GOP infighting
Tennessee House of Representatives
Now playing
03:08
GOP lawmaker applauded after praising three-fifths compromise
Getty Images/AP
Now playing
01:29
This is who Trump endorsed to replace Liz Cheney
Now playing
03:48
Why the GOP has false beef with Biden's climate plan
(CNN) —  

Michael Flynn, President Donald Trump’s former national security adviser, is turning to a lawyer who fanned conspiracy theories about investigators’ conduct in his case to represent him as he awaits sentencing.

Sidney Powell, a Texas-based former federal prosecutor and conservative-leaning political commentator, will represent Flynn after he fired his longtime legal counsel from the large Washington law firm Covington & Burling, according to two sources familiar with the development. Powell has not yet announced in court that she will represent Flynn.

The Hill first reported on Wednesday that Powell would represent Flynn.

Powell will be tasked with helping Flynn through what may be a contentious trial this summer against his former lobbying partner, where he will likely be a witness for the prosecution, and with attempting to win a judge’s sympathy at his sentencing after a disastrous hearing last December.

Powell and her law firm did not respond to multiple requests for comment from CNN this week. Lawyers from Covington & Burling have also declined to comment. In a statement to Axios, Powell said she was “honored” to represent Flynn and that he would continue to cooperate with the government.

A former federal prosecutor based in Texas, Powell has become known in recent years for her criticism of the Mueller investigation, especially on Fox News. She wrote a book focused on alleged prosecutorial misconduct in past major investigations – including the case against the late Alaska Sen. Ted Stevens, which Judge Emmet Sullivan dismissed because of how prosecutors had handled it.

She is also a frequent critic of top Mueller-team prosecutor Andrew Weissmann, who led the prosecution of former Trump campaign chairman Paul Manafort and did not appear publicly to be involved in the Flynn matter.

In an op-ed before Flynn’s aborted sentencing hearing last December, Powell pushed the idea that Flynn may not have received all of the relevant information in his case from prosecutors and the FBI, citing a rule requiring that defendants see evidence that might help them, which Flynn did after his plea because of an order from the judge.

“Mueller has shown abject contempt for the wrong court. Judge [Emmet] Sullivan is a real judge who believes in the rule of law and has the integrity to enforce it equally,” Powell wrote in the op-ed in The Daily Caller. “The evidence strongly suggests Mueller violated Brady, destroyed or suppressed evidence, and obstructed justice. He has disgraced himself and the Department of Justice. Mueller’s time is up.”

At the sentencing hearing, Sullivan harshly rejected a possible suggestion in a court memo from Flynn’s team that Flynn may not have accepted responsibility after he pleaded guilty, even after Mueller’s team gave him a glowing recommendation for little to no jail time. Flynn then said he fully accepted responsibility for lying to the FBI while he worked for the President and still wished to plead guilty. He asked to delay sentencing so he could continue to help prosecutors with their investigations. The sentencing has not been rescheduled.

Changing lawyers

Flynn’s lawyers Rob Kelner and Steve Anthony announced they were leaving his case last week. They had done legal work for Flynn’s lobbying group, called the Flynn Intel Group, and for Flynn during the Mueller investigation.

Flynn became one of the Mueller investigation’s earliest and most important cooperators in the obstruction investigation of Trump, after Flynn pleaded guilty to lying to the FBI. He also agreed to help prosecutors in other cases – and is expected to be the Justice Department’s star witness at the trial of his former lobbying partner regarding their work for Turkey.

That case has so far put Covington & Burling’s work for Flynn’s lobbying business in the spotlight, with prosecutors wanting to use information they gathered about it at trial. That could have potentially complicated those lawyers’ continued work for Flynn.

Flynn admitted in December 2017 to lying to the FBI while they had interviewed him in the White House in January 2017 about discussing foreign policy with then-Russian Ambassador Sergey Kislyak and about his lobbying for Turkey.

Once he agreed to help Mueller, the fired Trump adviser sat for 19 interviews with the special counsel’s office and other federal prosecutors.

He was set to be sentenced in December 2018 by Sullivan, yet the judge grew angry during the hearing at Flynn and his then-attorneys’ approach of pointing out the circumstances of his FBI interview and comparing it to the interviews of other Mueller defendants who pleaded guilty to lying.

“I am not hiding my disgust, my disdain, for your criminal offense,” Sullivan said in court.

Sullivan had asked Flynn’s team point-blank at the December hearing if he had been entrapped by the FBI. No, his attorney said then.

The attorneys then told the judge they took responsibility for alluding to the FBI’s approach in their court papers – saying it wasn’t Flynn’s decision.

Powell’s approach

Supporters of Flynn have continued to question the FBI and Mueller in the prosecution of Flynn, even pushing conspiracy theories that aren’t supported by the court record and the Mueller report regarding his case.

Some have called for Flynn to withdraw his guilty plea or to ask the court to throw out his case – a move that would be exceedingly difficult, since his guilty plea has already been accepted by the judge and Flynn has waived many of his rights. Plus, he is still likely to be subpoenaed to testify at the trial this summer.

It’s unclear what approach Powell will take with the court for Flynn, and if it would differ from what she’s pushed publicly.

Flynn’s new lawyer regularly shares right-wing conspiracies on social media. Just this month, she retweeted posts that said Flynn was the victim of the “Obama Deep State” and that the Trump campaign was surveilled by the FBI “to protect Hillary Clinton.” She also retweeted one unverified post that alleged that a Mueller probe witness had a stroke as a result of hardball tactics from prosecutors.

Regarding Flynn’s case, Powell retweeted posts that encouraged Trump to grant a pardon. She also retweeted posts that called on the judge to dismiss the case against Flynn. Trump has publicly floated the possibility of a pardon for his former national security adviser.

Powell attended the sentencing hearing in December, sitting alongside Flynn’s family.

CNN’s Marshall Cohen contributed to this report.