The New York Times reported May 8th,

WASHINGTON — Less than a week into the Trump administration, Sally Q. Yates, the acting attorney general, hurried to the White House with an urgent concern. The president’s national security adviser, she said, had lied to the vice president about his Russian contacts and was vulnerable to blackmail by Moscow.

“We wanted to tell the White House as quickly as possible,” Ms. Yates told a Senate Judiciary subcommittee on Monday. “To state the obvious: You don’t want your national security adviser compromised with the Russians.”

But President Trump did not immediately fire the adviser, Michael T. Flynn, over the apparent lie or the susceptibility to blackmail. Instead, Mr. Flynn remained in office for 18 more days. Only after the news of his false statements broke publicly did he lose his job on Feb. 13.

WASHINGTON, DC – MAY 8: Former Director of National Intelligence James Clapper (L) and former U.S. Deputy Attorney General Sally Yates testify before the Senate Judicary Committee’s Subcommittee on Crime and Terrorism in the Hart Senate Office Building on Capitol Hill May 8, 2017 in Washington, DC. Before being fired by U.S. President Donald Trump, Yates testified that she had warned the White House about contacts between former National Security Advisor Michael Flynn and Russia that might make him vulnerable to blackmail. (Photo by Eric Thayer/Getty Images)