Washington (CNN) Paul Manafort, the former Trump campaign chairman embattled by criminal indictments, may no longer fight the charges related to his Ukrainian lobbying operation.

He and the special counsel's office are close to a deal for a guilty plea ahead of his upcoming trial, according to a source familiar with the matter. A deal is expected but the source cautioned the two sides have been close before.

The incentive appears to be to reach a deal ahead of a pretrial motion hearing scheduled for Friday and before jury selection begins Monday in DC District Court. That's also a week before Manafort and prosecutors make new filings in Virginia to discuss the charges and convictions he faces there.

A plea Friday would bring to an end to one of the most active criminal cases in the DC federal court system this year. Manafort's lawyers have filed hundreds of pages in courts to fight prosecutors' allegations and have brought two appeals unsuccessfully, and his legal fees mounted to more than a million dollars, according to two people familiar with his case.

Proceedings scheduled for Monday would kick off a second grueling, expensive, politically explosive three-week-or-longer trial in federal court. Manafort faces seven counts of foreign lobbying violations, money laundering conspiracy and witness tampering. The trial was likely to put on display the secret dealings of Washington's lobbying and law firm elite.

Manafort is accused in DC of not disclosing to the Justice Department his work for Ukrainian politicians and laundering that income. Prosecutors allege he set up meetings with lawmakers and fashioned public relations efforts in the US on the Ukrainians' behalf.

A jury convicted Manafort in Virginia last month on eight bank and tax fraud charges related to his lobbying wealth after a three-week trial. The evidence was largely about how he had kept money off his books and relied on others to help him lie to banks and the government. At trial, prosecutors showed how Manafort worked for pro-Russian Ukrainians and funneled millions of dollars in income through Cypriot accounts.

It was not clear if the deal with the special counsel's office would include cooperation. The plea is expected to address both sets of charges he faces -- for the upcoming trial in DC and the 10 counts he still faces in Virginia.

Manafort has not yet entered a new plea before the judge in DC and prosecutors have not yet revealed the terms of any deal reached with him. If a deal comes through, it will likely be announced at the court hearing at 11 a.m. Friday.

Plea signs

In the last few days, the prosecutors' activities shifted from trial preparation to negotiations, according to a person familiar with the case.

Then indications added to the possibility that a plea deal was in the works. Members of Manafort's legal team were spotted spending several hours at the special counsel office's Thursday, even sending a junior member of the defense team to bring lunch inside. Uzo Asonye, a prosecutor who tried Manafort's case in Virginia, was also at the office Thursday.

Several news outlets reported on possible ongoing talks this week. ABC News reported Thursday evening that Manafort had tentatively agreed to a deal.

The judge overseeing his case in DC, Amy Berman Jackson, delayed a major court hearing about his upcoming trial twice this week. First, she moved it from Wednesday to Friday. Then, as lawyers inside the special counsel's office began to leave Thursday, the judge pushed the hearing back another hour and a half Friday morning, giving no reason.

Months of pressure

Manafort has maintained that he is not guilty since special counsel Robert Mueller's office first charged him with foreign lobbying and financial crimes last October. But he has had several reasons to cut a deal. With it, he could lessen the risk of another conviction and of harsh sentences, escape paying thousands of dollars for three or more lawyers to try the case and avoid the attention on himself, his associates and family.

His unwillingness to cooperate with prosecutors since before his indictment has unspooled into several sets of new charges, making his case more complicated.

Adding to the complications in the negotiations, Manafort's legal team has attempted to preserve the possibility of a presidential pardon, the prospect of which a lawyer for President Donald Trump suggested to members of his earlier legal team, according to people briefed on the matter.

After the first indictment in October, the White House distanced itself from Manafort and downplayed his time leading the Trump campaign. But in recent weeks, as Manafort faced a conviction in his related case in Virginia, Trump sympathized with him.

"I feel very badly for Paul Manafort and his wonderful family," the President tweeted the week of his conviction. " 'Justice' took a 12 year old tax case, among other things, applied tremendous pressure on him and, unlike Michael Cohen, he refused to 'break' - make up stories in order to get a 'deal.' Such respect for a brave man!"

Manafort, Trump's top political operative from May to August 2016, has long been considered one of the bigger fish for the special counsel's office to hook in its probe into Russian interference in the 2016 election and possible coordination with the Trump campaign. In addition to the financial and lobbying charges against Manafort, the special counsel's team has said it's investigating allegations he colluded with Russia while working for Trump.

It is not known the extent that Manafort was still in touch with his Russia-friendly clients from Ukraine in 2015 and 2016, though even after his arrest he has stayed in touch with a Russian associate, Konstantin Kilimnik, whom prosecutors say has ties to the country's military intelligence agency.

Speculation that Manafort could flip to help prosecutors has built since his first charge, even leading to a judge in Virginia accusing prosecutors of trying to get Manafort to "sing" and "get" Trump. "You really care about what information Mr. Manafort can give you that would reflect on Mr. Trump or lead to his prosecution or impeachment or whatever. That's what you're really interested in," Judge T.S. Ellis said in court in Virginia in May.

One year under indictment

Over the past months, Manafort's legal options slimmed as the special counsel notched several wins against him, including sending him to jail, securing several cooperators and gaining convictions.

Manafort's case marked the first indictment in Mueller's investigation. The allegations revealed last October reiterated a year of news reports that Manafort had secretly funneled income from Ukrainian lobbying contacts for years.

After his arrest in October, he was detained by the court in his Alexandria, Virginia, home for more than eight months.

Prosecutors pressured Manafort further when they filed new mortgage and tax fraud charges against him in February -- weeks after they discovered he was offering to secure his bail with homes tied up in his alleged mortgage fraud.

At the time, prosecutors gave Manafort the option of keeping all his charges in the DC federal court. Instead, he gambled on splitting the case into two trial tracks, in two demographically different courts.

Prosecutors also gained the cooperation of his longtime associate Rick Gates, who had been indicted alongside him. Gates pleaded guilty in February to helping Manafort use bank accounts in Cyprus and Grenadines to hide millions they had made while lobbying for Ukrainian politicians. Gates testified against Manafort in the Virginia trial, saying his former boss had directed him to commit the fraud.

The special counsel's office added a second potential cooperator against Manafort in late August when another lobbyist for Ukrainians, Sam Patten, pleaded guilty to a foreign lobbying charge. Patten's name is likely to appear in evidence against Manafort, prosecutors said, and he has agreed to help the special counsel's office as part of his plea. Patten worked with Manafort's Russian associate Kilimnik through 2017 and admitted in court to illegally using a straw purchaser to buy Trump inaugural tickets for an oligarch.

In June, prosecutors won another boost when a DC-based grand jury added witness tampering charges to Manafort's indictment.

Manafort and Kilimnik were accused by prosecutors of reaching out to potential witnesses in his case and coaching their possible testimony. Kilimnik has not appeared in US court or entered any plea. He has not been charged with other crimes.

After the witness tampering accusation surfaced, a federal judge in DC revoked Manafort's bail, sending him to jail. He is still being detained in Alexandria.

On August 21, prosecutors won the first conviction of Manafort following the trial. Though the Virginia jurors convicted him of eight counts, they deadlocked on 10 remaining charges, splitting 11 guilty votes to one not guilty. The judge declared a mistrial on those counts. Prosecutors had not yet said what they'd do with those charges, and Manafort had not yet appealed the conviction.