WASHINGTON — A lawyer for Paul Manafort, the president’s onetime campaign chairman, repeatedly briefed President Trump’s lawyers on his client’s discussions with federal investigators after Mr. Manafort agreed to cooperate with the special counsel, according to one of Mr. Trump’s lawyers and two other people familiar with the conversations.
The arrangement was highly unusual and inflamed tensions with the special counsel’s office when prosecutors discovered it after Mr. Manafort began cooperating two months ago, the people said. Some legal experts speculated that it was a bid by Mr. Manafort for a presidential pardon even as he worked with the special counsel, Robert S. Mueller III, in hopes of a lighter sentence.
Rudolph W. Giuliani, one of the president’s personal lawyers, acknowledged the arrangement on Tuesday and defended it as a source of valuable insights into the special counsel’s inquiry and where it was headed. Such information could help shape a legal defense strategy, and it also appeared to give Mr. Trump and his legal advisers ammunition in their public relations campaign against Mr. Mueller’s office.
For example, Mr. Giuliani said, Mr. Manafort’s lawyer Kevin M. Downing told him that prosecutors hammered away at whether the president knew about the June 2016 Trump Tower meeting where Russians promised to deliver damaging information on Hillary Clinton to his eldest son, Donald Trump Jr. The president has long denied knowing about the meeting in advance. “He wants Manafort to incriminate Trump,” Mr. Giuliani declared of Mr. Mueller.
While Mr. Downing’s discussions with the president’s team violated no laws, they helped contribute to a deteriorating relationship between lawyers for Mr. Manafort and Mr. Mueller’s prosecutors, who accused Mr. Manafort of holding out on them despite his pledge to assist them in any matter they deemed relevant, according to the people. That conflict spilled into public view on Monday when the prosecutors took the rare step of declaring that Mr. Manafort had breached his plea agreement by lying to them about a variety of subjects.
Mr. Manafort’s lawyers insisted that their client had been truthful but acknowledged that the two sides were at an impasse. Mr. Manafort will now face sentencing on two conspiracy charges and eight counts of financial fraud — crimes that could put him behind bars for at least 10 years.
Mr. Downing did not respond to a request for comment. Though it was unclear how frequently he spoke to Mr. Trump’s lawyers or how much he revealed, his updates helped reassure Mr. Trump’s legal team that Mr. Manafort had not implicated the president in any possible wrongdoing.
Mr. Giuliani, who has taken an aggressive posture against the Russia investigation since Mr. Trump hired him in April, seized on Mr. Downing’s information to unleash lines of attack onto the special counsel.
In asserting that investigators were unnecessarily targeting Mr. Trump, Mr. Giuliani accused the prosecutor overseeing the Manafort investigation, Andrew Weissmann, of keeping Mr. Manafort in solitary confinement simply in the hopes of forcing him to give false testimony about the president.
But detention officials decide whether inmates serve in solitary confinement, according to law enforcement officials, and allies of Mr. Manafort have said he is there for his own safety.
A spokesman for Mr. Mueller’s office declined to comment. Mr. Weissmann is a longtime senior Justice Department prosecutor who specializes in prosecuting financial crimes and turning defendants into cooperating witnesses. His aggressive nature has earned him two competing reputations: Prosecutors view him as a relentless investigator who has overseen some of the Justice Department’s most complex investigations, but some defense lawyers say he is overly combative and will bend the facts to gain a conviction.
In his own recent Twitter attacks on the special counsel, the president seemed to imply that he had inside information about the prosecutors’ lines of inquiry and frustrations. “Wait until it comes out how horribly & viciously they are treating people, ruining lives for them refusing to lie,” Mr. Trump wrote on Tuesday.
Earlier this month, he tweeted: “The inner workings of the Mueller investigation are a total mess. They have found no collusion and have gone absolutely nuts. They are screaming and shouting at people, horribly threatening them to come up with the answers they want.”
Mr. Manafort’s legal team had long kept Mr. Trump’s lawyers abreast of developments in his case under a joint defense agreement. The president’s team has pursued such pacts as a way to monitor the special counsel’s inquiry. Mr. Giuliani said last month that the president’s lawyers had agreements with lawyers for 32 witnesses or subjects of Mr. Mueller’s 18-month-old investigation.
Defense lawyers involved in investigations with multiple witnesses often form such alliances so they can share information without running afoul of attorney-client privilege rules. But when one defendant decides to cooperate with the government in a plea deal, that defense lawyer typically pulls out rather than antagonize the prosecutors who can influence the client’s sentence. For instance, a lawyer for the president’s former national security adviser Michael T. Flynn withdrew last year from such an agreement with Mr. Trump’s lawyers before Mr. Flynn pleaded guilty to a felony offense and agreeing to help the special counsel.
Mr. Manafort’s lawyers, on the other hand, maintained their joint defense agreement with the president’s legal team even after Mr. Manafort pleaded guilty to two conspiracy counts in September and began answering questions in at least a dozen sessions with the special counsel.
Trump is an un-indicted co-conspirator, who has lied to the FBI in writing and committed TAX FRAUD! Nixon original sin was… TAX FRAUD! That is why we had a tradition of seeing the TAXES!!!!