A longtime private attorney for President Trump said he has advised the White House that Trump should hire a “tough Washington lawyer” to help navigate an increasingly complex legal strategy in response to the special counsel investigation of alleged ties between the presidential campaign and Russia.

“He needs a good lawyer, someone who is strong, not that he would go against the lawyer’s advice, but everybody should have a lawyer who sees things through and comes up with good advice,” said Jay Goldberg, who represented Trump from 1990 to 2005, including during his two divorces and other high-profile cases.

Trump’s need for a private attorney is viewed as a high priority because he so far has been relying on government lawyers, including his White House counsel, who could eventually be called to testify about their private conversations with him. Such conversations are not considered “privileged,” unlike what Trump experienced as a corporate executive working with hired legal counsel.

The recommendation comes as the White House’s legal strategy is being complicated by Trump’s tweets and other statements, potentially undermining his ability to declare protection under executive privilege, legal analysts said Thursday.

Trump’s constant tweeting about subjects under investigation — as well as his claim that then-FBI Director James B. Comey assured him in three conversations that he was cleared — could undermine efforts to cite executive privilege, analysts said.

(Victoria Walker,Jayne Orenstein,Dalton Bennett,Jenny Starrs/The Washington Post)

“It makes it extremely hard for him to make a claim of executive privilege after he has already put it out there publicly,” said Mark J. Rozell, dean of the Schar School of Public Policy at George Mason University and author of a book on executive privilege. “He is just not careful. We know that.”

Moreover, Rozell said, citing privilege inevitably would raise suspicions that he has something to hide. Trump on Thursday responded to the Wednesday appointment of Special Counsel Robert S. Mueller III by tweeting: “This is the single greatest witch hunt of a politician in American history!”

Rozell said Trump’s attitude should be that he has “nothing to hide,” but Rozell said Trump’s tweet heightened concerns that he won’t fully cooperate.

Even if Trump does cite executive privilege, the practice has grown weaker in recent years — and was criticized by Trump himself when it was invoked by President Barack Obama.

Executive privilege, while not outlined in the Constitution, has been cited by a number of presidents as the rationale for withholding certain information, often on grounds of national security. But it has also been seen by courts as a way to hide information that is pertinent to an investigation, and the privilege has sometimes been rejected and is not considered absolute.

Five years ago, Trump mocked Obama for citing executive privilege in refusing to turn over records demanded as part of a congressional investigation. Trump’s view was shared by many Republicans, and the courts eventually agreed, issuing a 2016 ruling that underscored the difficulty of a president to withhold information from investigators.

Another complication for Trump is that he has relied on the advice of White House Counsel Donald McGahn, whose background is in election law. Trump, for example, told NBC News last week that McGahn did not convey that it was an “emergency” to remove national security adviser Michael Flynn from his post. McGahn had been told by then-acting attorney general Sally Yates that Flynn had been compromised as a result of his discussions with the Russian ambassador, but Flynn was not fired for 18 days.

(Peter Stevenson,Jason Aldag,Whitney Leaming/The Washington Post)

A White House counsel is supposed to have a higher allegiance to the office of the presidency than to the president who occupies the office, legal experts said. McGahn could be asked to testify and might have to reveal the content of his conversations with the president.

John Dean, the White House counsel during the Nixon administration, said that in the wake of post-Watergate reforms, the counsel is required to report wrongdoing even if he learned about it in a private conversation.

“If Trump says, ‘I want to cover this up and the hell with everybody,’ that’s something that the White House counsel will have to wrestle with and do what is right for the office and not what is right for Trump,” Dean said in an interview. Dean served during the Watergate scandal and famously testified about how he told President Richard M. Nixon that there was a cancer growing on his presidency. Dean pleaded guilty to one count of obstruction of justice for his role in Watergate affair.

Trump has the option of hiring a private attorney, as do members of his staff who might be drawn into the investigation.

The White House declined to comment.

Legal experts interviewed Thursday said that the White House Counsel’s Office should be scrambling to prepare for a wide-ranging probe. Typical steps would include issuing a memo to all staffers warning them not to destroy any records that might be sought by the special counsel.

One aspect of the case likely to be investigated by Mueller, as well as congressional committees, is that Trump allegedly asked Comey to end his investigation into Flynn. Trump initially tweeted that Comey should hope that there are no “tapes” of a January dinner conversation, which prompted Comey allies to describe a memo that quotes Trump urging that the Flynn investigation come to an end.

Under his appointment, Mueller has broad authority to investigate matters that come up during his probe of whether Russia had ties to the Trump campaign. That could enable him to look into whether Trump or his aides tried to cover up matters such as efforts to halt the Flynn investigation.

Goldberg, the former Trump attorney, said the president is being unfairly treated. He said that in his experience Trump was “the perfect client. He listens. He does not presume to overrule the lawyer.”