WASHINGTON — A lawyer for President Trump called on the Justice Department on Saturday to end the special counsel investigation into ties between Russia and the Trump campaign, shifting abruptly to a more adversarial stance as the inquiry appeared to be intensifying.
The comments by the lawyer, John Dowd, were prompted by the firing late on Friday of the former deputy F.B.I. director Andrew G. McCabe. Mr. Dowd exhorted Rod J. Rosenstein, the deputy attorney general, who oversees the special counsel, to end the inquiry and accused the former F.B.I. director James B. Comey of concocting a baseless investigation.
"I pray that Acting Attorney General Rosenstein will follow the brilliant and courageous example of the F.B.I. Office of Professional Responsibility and Attorney General Jeff Sessions and bring an end to alleged Russia collusion investigation manufactured by McCabe's boss James Comey based upon a fraudulent and corrupt dossier," Mr. Dowd told The Daily Beast.
His remarks capped another round of revelations in recent days that reinvigorated or displayed Mr. Trump's frustrations with the investigation, which has cast a shadow over his presidency. He was said to be angered over a New York Times report that records from the Trump Organization were subpoenaed, and he celebrated the firing of Mr. McCabe, who was among the first F.B.I. officials to scrutinize possible links between Russia and the Trump team, calling his dismissal a "great day for Democracy" on Twitter.
Mr. Dowd, by contrast, did not name the special counsel in his statement, but the implication that he believed Mr. Mueller should be fired was unmistakable. Such a move could set off alarms among Republicans in Congress, who have largely stood by as the president repeatedly assailed the Justice Department and the F.B.I.
People close to the president were skeptical that Mr. Dowd was acting on his own. Mr. Trump has a history of using advisers to publicly test a message, giving him some distance from it. And Mr. Dowd's comments came at a time when members of Mr. Trump's legal team are jockeying to stay in his favor.
Hours later, the president echoed Mr. Dowd's accusations of corruption in the theoretical "deep state" that Mr. Trump has long cast as a boogeyman working to undermine him.
"There was tremendous leaking, lying and corruption at the highest levels of the FBI, Justice & State," he wrote on Twitter.
The president's tweets, posted on a Saturday in which he remained inside the White House with no public schedule, came as Mr. Mueller is said to have sent questions to Mr. Trump's legal team as part of negotiations over an interview with the president. Mr. Mueller is seeking the interview, according to two people close to the White House, in order to ask follow-up questions, but put forward the list as a start.
Mr. Dowd's remarks about Mr. Mueller's investigation represented an extraordinary shift in public strategy for the Trump legal team. Since taking over the case last summer, Mr. Trump's lawyers have urged a strategy of restraint, in which the president avoids discussing Mr. Mueller or criticizing him, and the lawyers had done nothing publicly until now that could agitate the special counsel's team.
The comments by both Mr. Trump and Mr. Dowd lent credence to Mr. McCabe's assertion that the president sees his firing as directly tied into Mr. Mueller's case. Mr. McCabe, who is a potential witness in the investigation, declared that his dismissal was an attempt to undermine it.
Mr. Sessions fired Mr. McCabe for failing to be forthcoming with the department's internal watchdog about a conversation he authorized between F.B.I. officials and a journalist.
Like Mr. Comey, Mr. McCabe also kept contemporaneous memos about his interactions with the president and his conversations with Mr. Comey, a person close to Mr. McCabe said on Saturday.
The memos could support the account of Mr. Comey, who described in his memos and congressional testimony repeated requests from the president to clear his name. Mr. Comey said Mr. Trump also asked him to end an investigation into his former national security adviser, Michael T. Flynn. The special counsel is investigating both matters.
Mr. McCabe's memos were left at the F.B.I., which means that Mr. Mueller's investigators have access to them as they work to corroborate Mr. Comey's account.
Mr. McCabe's lawyers had no comment on Saturday, and Mr. Rosenstein has repeatedly defended the special counsel, including in an interview this month with USA Today, in which he said he had seen no need to fire Mr. Mueller.
Mr. Comey, who has a book scheduled to be published next month, weighed in himself.
The president's supporters have tried to undercut the investigation as part of a broader attempt to clear him of wrongdoing. This month, Republicans on the House Intelligence Committee — which is led by a close ally of the president, Representative Devin Nunes of California — concluded their own investigation into Russia's election meddling, saying they had determined the president did nothing wrong. Democrats on the panel accused Republicans of putting partisan politics ahead of fact finding.
Mr. Trump, who has repeatedly criticized Mr. McCabe's wife for accepting hundreds of thousands of dollars in donations from a political committee tied to Terry McAuliffe, a Hillary Clinton ally, for a Virginia State Senate race, praised Mr. McCabe's ouster again on Saturday.
Mr. Trump has increasingly expressed frustration as the special counsel investigation has shown more signs of accelerating rather than ending. His legal team has worked to keep him from firing Mr. Mueller in the past. To keep the president at bay, the lawyers — led by the White House lawyer Ty Cobb — told him that Mr. Mueller's investigation would be over by last December and that they would ask Mr. Mueller to put out a statement saying the president was not a target of the investigation.
But instead, Mr. Trump was livid anew this week over the Times report that Mr. Mueller had subpoenaed his corporate records, including those related to Russia, according to one person close to the White House.
The president's lawyers appear to be feeling increasingly uneasy about where they stand. This month, Mr. Trump met with a veteran Washington lawyer, Emmet T. Flood, to discuss coming on board to take over the president's dealings with Mr. Mueller's office and possibly replacing Donald F. McGahn II as White House counsel. The president's personal lawyers, Mr. Dowd and Jay Sekulow, did not know about the meeting, prompting concerns that they could be pushed aside, and potentially making them less resistant to Mr. Trump's whims about handling the inquiry.
Last June, Mr. Trump backed down from his demand that Mr. Mueller be fired after Mr. McGahn threatened to quit. A month later, Mr. Trump said in an interview with The Times that the special counsel would be crossing a red line if he looked into his family's finances beyond any relationship with Russia. After the Trump Organization subpoena was revealed on Thursday, Mr. Trump's lawyers privately tried to play it down, in part to keep the president and his family calm.
Mr. Dowd has been at the center of a string of embarrassing episodes in recent months. In December, he said he had written a tweet posted by the president that implied Mr. Trump knew that Mr. Flynn had lied to the F.B.I. when Mr. Trump fired him.
Months earlier, Mr. Dowd was overheard by a Times reporter discussing details of a dispute inside the president's legal team over lunch at a Washington steakhouse.
Democrats seized on Mr. Dowd's statement on Saturday. Senator Mark Warner of Virginia, the top Democrat on the Senate Intelligence Committee, called on lawmakers of both parties to defend Mr. Mueller.
Michael S. Schmidt reported from Washington, and Maggie Haberman from New York. Matt Apuzzo contributed reporting from Washington.
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