(CNN) Donald Trump is beside himself with fury ahead of what could turn out to be one of the most pivotal days yet in the Russia investigation.

The President unleashed a seething Twitter blast early Friday as special counsel Robert Mueller prepared to unveil new details of his probe into two key former Trump associates, Paul Manafort and Michael Cohen. His work could make life in the Oval Office even more uncomfortable.

In a rant extraordinary even by the standards of his searing morning tweetstorms, the President claimed Mueller's team was tainted by conflicts of interest and stacked with Democrats. He also asked whether the final report would criticize his political nemeses such as former FBI Director James Comey and Hillary Clinton.

"Will Robert Mueller's big time conflicts of interest be listed at the top of his Republicans only Report," Trump wrote, before turning on the special counsel's top lieutenant.

"Will Andrew Weissman's horrible and vicious prosecutorial past be listed in the Report. He wrongly destroyed people's lives, took down great companies..."

Mueller is facing a deadline to explain to a judge in Washington why he has accused Manafort, Trump's already convicted and jailed former campaign chairman, of lying and breaking a cooperation deal.

And he must also deliver documents to a court in New York recommending whether Cohen, Trump's former personal lawyer, should go to jail and for how long, after Cohen turned against his former top client and agreed to cooperate with the special counsel.

"A total witch hunt," Trump said at one point, repeating his preferred moniker for the Mueller investigation.

The twin filings represent yet another dramatic moment for the Mueller investigation and are being eagerly awaited in Washington for signs of how the Russia drama will unfold in the weeks ahead and how much it may eventually hurt Trump.

Yet as with this week's feverishly anticipated sentencing memo about Trump's ex-national security adviser Michael Flynn, the filings could bring a measure of disappointment to special counsel watchers if large quantities of evidence are redacted to protect ongoing investigations.

Even if important context remains under seal, Mueller often delivers hints and opens loops in court documents that sketch a colorful narrative of the Russia affair, and may offer pointers of where a probe branded "presidential harassment" by Trump on Thursday is going.

Neither of Friday's deadlines involves action implicating the President directly in any wrongdoing, more than 18 months after Mueller was chosen to find out whether Trump's campaign colluded with Russian election interference in 2016.

But in recent weeks it has become clear that the special counsel is using proceedings and filings concerning key witnesses and former Trump associates to suggest a pattern of questionable behavior on the part of the President.

It's clear that Trump's behavior has worried officials at the Justice Department since nearly the start of his presidency. CNN reported Thursday on the frantic days that followed the President's firing of then-FBI Director James Comey , which led Deputy Attorney General Rod Rosenstein and top FBI officials to view Trump as a leader who needed to be reined in, according to two sources describing the sentiment at the time. Ultimately, then-acting FBI Director Andrew McCabe took the extraordinary step of opening an obstruction of justice investigation even before Mueller was appointed, the sources said.

Since then, Mueller has constructed a tapestry of disclosures that started with an accounting of a hacking operation by Moscow's intelligence agencies and has unveiled multiple links between Russians and people around Trump -- and repeated lies about those contacts.

Friday's activity will end an ominous week for Trump in which it has become clear that the investigation is far broader beneath the surface than is publicly evident. Mueller can now be said to be digging into possible collusion with the Russians, obstruction of justice, contacts with Russian officials during Trump's transition, possible campaign finance violations and the President's business secrets.

A frantic Friday revolving around the Russia drama also features a return to center stage by Comey, who is testifying in private to two House committees as Republicans throw their final blocks for Trump before handing over control to Democrats next month. A transcript of the encounter is expected to be released within 24 hours.

And a former Trump campaign foreign policy adviser, George Papadopoulos, was released from prison in Wisconsin after serving a 14-day sentence for lying to the FBI.

In another development that could affect the Mueller probe, Trump said he would nominate William Barr as attorney general to fill a post Barr also held in the administration of President George H.W. Bush. Barr is seen as a mainstream choice, though has previously criticized aspects of the Russia investigation. If confirmed by the Senate, he would be responsible for overseeing the special counsel.

If that were not enough, Trump's longtime informal political adviser Roger Stone -- who is being investigated for alleged cooperation with WikiLeaks, which posted emails hacked from the Hillary Clinton campaign and the Democratic National Committee by Russian agents -- said he would not turn against the President.

"This is not about Russian collusion, it's about the parsing of words," Stone said. "It's about process crimes and perjury traps, and I decline to participate."

'Crimes and lies'

Mueller has pledged to tell the court abou t Manafort's "crimes and lies" t hat he said were committed after the uber-lobbyist signed a plea agreement and have sparked speculation the former campaign chairman is angling for a presidential pardon.

The disclosures from Mueller's team will be closely watched to see whether Manafort, who is at risk of spending the rest of his life in jail, lied about activity that could implicate Trump or senior campaign officials, or solely about the business interests in Ukraine that led to his downfall on fraud charges or other questions.

Manafort is an important witness for Mueller since he was at a notorious Trump Tower meeting in 2016 in which the candidate's son Don Jr. believed Russian intermediaries would deliver "dirt" on Clinton.

He could also be useful in establishing wheth er changes to the platform at the Republican National Convention that watered down criticism of Russia had followed requests from Moscow.

Lawyers for Manafort denied their client lied and will have a chance to challenge the special counsel's assertions before his sentencing date of March 5.

It is possible that some of Mueller's explanations will be blacked out, as they were in the Flynn filing. But a spokesman for the special counsel's office has said that at least some of the filing will be public.

Ross Garber, a lawyer who specializes in impeachment, told CNN's "New Day" on Thursday that it was not normal for a cooperation agreement to collapse in such a manner, given the intensive negotiations that typically happen beforehand.

"It will be interesting to see whether anything new came up that nobody expected, but it is very unusual," Garber said.

Mueller's decision to come down hard on Manafort but to offer leniency to Flynn was widely interpreted as a sign that he will reward people implicated in the investigation who are willing to tell the truth about what happened -- but will tolerate no obstruction.

Cohen resets his life's 'compass'

Cohen has asked the court for a non-custodial sentence after he admitted tax fraud and lying to Congress about Trump's business aspirations in Moscow to preserve the President's political narrative that he had no ties to Russia.

Cohen's lawyers said in a memo that their client -- by turning on Trump, for whom he once said he would take a bullet -- had decided to "re-point his internal compass true north toward a productive, ethical and thoroughly law-abiding life."

Sentencing documents filed by both sides in the case have connected significant dots in the investigation.

Last week, Cohen pleaded guilty to misleading lawmakers about a project to build a Trump Tower in Moscow, which he had originally said had been shelved by January 2016.

In fact, the project was alive until June 2016, according to a statement lodged with the court by Mueller, who said Cohen had discussed the plan with Trump several times and had briefed Trump family members.

The revelations were important because Trump had insisted throughout the campaign that he had no business links with Russia.

They also raised the question of whether the President was beholden to Russia for a long period of the campaign and was shaping his complimentary statements about President Vladimir Putin to further his own financial interests.

Cohen has also pleaded guilty to campaign finance violations connected to hush money paid to women who alleged affairs with Trump, which the President has denied.

"Michael kept his client contemporaneously informed and acted on his client's instructions," Cohen's lawyers wrote in their sentencing memo.

"Michael felt obligated to assist Client-1, (Trump) on Client-1's instruction, to attempt to prevent Woman-1 and Woman-2 from disseminating narratives that would adversely affect the Campaign and cause personal embarrassment to Client-1 and his family."

Cohen, who faced 46 to 63 months in jail under his original plea deal with New York prosecutors, is hoping that Mueller will grant him the same kind of favorable treatment as Flynn. The special counsel told a court this week that owing to Flynn's cooperation with the investigation, the former national security adviser should get no jail time. Redactions in documents accompanying the request made it impossible, however, to assess what that cooperation entailed and whether it put the President in any jeopardy.

Trump has reacted angrily to the idea that Cohen could get a break from Mueller in return for his cooperation.

"He lied for this outcome and should, in my opinion, serve a full and complete sentence," the President tweeted earlier this week.

Depending on the details Mueller chooses to unveil on Friday, it is almost certain that Trump's allies will reach for their familiar argument that the special counsel still has not proved any cooperation between Russia and the campaign -- the original mandate of the probe.

But with every move he makes, Mueller appears to be getting closer to the people who are closest to the President himself, so in the broadest sense there's every chance that Friday could effectively be another rough day in court for Trump.

This post has been updated to include additional developments.