By Michael S. Schmidt, Matt Apuzzo and Maggie Haberman
WASHINGTON – Lawyers for Michael Flynn, President Donald Trump's former national security adviser, notified the president's legal team in recent days that they could no longer discuss the special counsel's investigation, according to four people involved in the case, an indication that Flynn is cooperating with prosecutors or negotiating a deal.
Flynn's lawyers had been sharing information with Trump's lawyers about the investigation by the special counsel, Robert Mueller, who is examining whether anyone around Trump was involved in Russian efforts to undermine Hillary Clinton's presidential campaign.
That agreement has been terminated, the four people said. Defense lawyers frequently share information during investigations, but they must stop when doing so would pose a conflict of interest. It is unethical for lawyers to work together when one client is cooperating with prosecutors and another is still under investigation.
The notification alone does not prove that Flynn is cooperating with Mueller. Some lawyers withdraw from information-sharing arrangements as soon as they begin negotiating with prosecutors. And such negotiations sometimes fall apart.
Still, the notification led Trump's lawyers to believe that Flynn – who, along with his son, is seen as having significant criminal exposure – has, at the least, begun discussions with Mueller about cooperating.
Lawyers for Flynn and Trump declined to comment. The four people briefed on the matter spoke on the condition of anonymity because they were not authorized to discuss it publicly.
A deal with Flynn would give Mueller a behind-the-scenes look at the Trump campaign and the early tumultuous weeks of the administration. Flynn was an early and important adviser to Trump, an architect of Trump's populist "America first" platform and an advocate of closer ties with Russia.
His ties to Russia predated the campaign – he sat with President Vladimir Putin at a 2015 event in Moscow – and he was a point person on the transition team for dealing with Russia.
The White House had been bracing for charges against Flynn in recent weeks, particularly after charges were filed against three other former Trump associates: Paul Manafort, his campaign chairman; Rick Gates, a campaign aide; and George Papadopoulos, a foreign policy adviser.
But none of those men match Flynn in stature, or in his significance to Trump. A retired three-star general, Flynn was an early supporter of Trump's and a valued surrogate for a candidate who had no foreign policy experience. Trump named him national security adviser, he said, to help "restore America's leadership position in the world."
Among the interactions that Mueller is investigating is a private meeting that Flynn had with the Russian ambassador and Jared Kushner, the president's son-in-law, during the presidential transition. In the past year, it has been revealed that people with ties to Russia repeatedly sought to meet with Trump campaign officials, sometimes dangling the promise of compromising information on Clinton.
Flynn is regarded as loyal to Trump, but he has in recent weeks expressed serious concerns to friends that prosecutors will bring charges against his son, Michael Flynn Jr., who served as his father's chief of staff and was a part of several financial deals involving the elder Flynn that Mueller is scrutinizing.
The White House has said that neither Flynn nor other former aides have incriminating information to provide about Trump. "He likes Gen. Flynn personally, but understands that they have their own path with the special counsel," a White House lawyer, Ty Cobb, said in an interview last month with The New York Times. "I think he would be sad for them, as a friend and a former colleague, if the process results in punishment or indictments. But to the extent that that happens, that's beyond his control."
Flynn was supposed to have been the cornerstone of Trump's national security team. Instead, he was forced out after a month in office over his conversations with the Russian ambassador, Sergey I. Kislyak. Flynn's handling of those conversations fueled suspicion that people around Trump had concealed their dealings with Russians, worsening a controversy that has hung over the president's first year in office.
Four days after Trump was sworn in, the FBI interviewed Flynn at the White House about his calls with the ambassador. U.S. intelligence and law enforcement agencies became so concerned about Flynn's conversations and false statements about them to Vice President Mike Pence that the acting attorney general, Sally Q. Yates, warned the White House that Flynn might be compromised.
The conversations with the Russian ambassador that led to Flynn's undoing took place during the presidential transition. When questions about them surfaced, Flynn told Pence that they had exchanged only holiday greetings – the conversations happened in late December, around the time that the Obama administration was announcing sanctions against Russia.
While Pence and White House press officers repeated the holiday-greetings claim publicly, Flynn and the ambassador had in fact discussed the sanctions. That invited the idea that the incoming administration was trying to undermine the departing president and curry favor with Moscow.
Trump sought Flynn's resignation only after news broke that Flynn had been interviewed by FBI agents and that Yates had warned the White House that his false statements could make him vulnerable to Russian blackmail.
Since then, Flynn's legal problems have grown. It was revealed that he failed to list payments from Russia-linked entities on financial disclosure forms. He did not mention a paid speech he gave in Moscow, as well as other payments from companies linked to Russia.
Former FBI Director James Comey has testified before Congress that Trump asked him to end the government's investigation into Flynn in a one-on-one meeting in the Oval Office the day after Flynn was fired. Trump's request caused great concern for Comey, who immediately wrote a memo about his meeting with the president.
And investigators working for Mueller have questioned witnesses about whether Flynn was secretly paid by the Turkish government during the presidential campaign. Flynn belatedly disclosed, after leaving the White House, that the Turkish government had paid him more than $500,000.
Flynn's firing was, in some ways, the first domino that set off a cascade of problems for Trump. After the president ousted Comey, news surfaced that the president had requested an end to the Flynn inquiry, a revelation that led to Mueller's appointment. That, in turn, raised the profile of an investigation that the president had tried mightily to contain.