Here are the important dates detailing Michael Flynn’s relationship with Russia that led to his resignation.

Now that former national security aide Michael Flynn is working with prosecutors on the Russia investigation, President Trump’s critics are reviving a familiar Watergate-era question.

What did the president know and when did he know it?

That question surfaced again Saturday after Trump tweeted that he fired Flynn because he lied to both him and the FBI, a statement that some observers said buttresses claims that the president tried to obstruct justice.

“I had to fire General Flynn because he lied to the Vice President and the FBI. He has pled guilty to those lies,” Trump tweeted. “It is a shame because his actions during the transition were lawful. There was nothing to hide!”

Some critics pointed out that Trump’s tweet implies he knew Flynn had lied to the FBI when he fired him — and before he reportedly asked former FBI Director James Comey to go easy on Flynn.

“If that is true, Mr. President, why did you wait so long to fire Flynn? Why did you fail to act until his lies were publicly exposed? And why did you pressure Director Comey to ‘let this go?'” tweeted Rep. Adam Schiff, D-Calif., top Democrat on the House Intelligence Committee.

Reports Saturday night indicated that Trump associates were trying to put distance between the president himself and the tweet.

According to The Associated Press, one person familiar with the situation said the tweet was actually crafted by John Dowd, one of the president’s personal attorneys.

The New York Times, citing two people briefed on the matter, also said the tweet was composed by Dowd, who was in contact with Trump on Friday and Saturday, trying to calm him after Flynn’s guilty plea.

Dowd apologized to White House officials for the tweet, according to the Times, saying he should have been more careful with his language in trying to parrot a statement released on Friday by another Trump lawyer, Ty Cobb.

Trump has denied pressuring Comey with respect to the Russia investigation.

MORE: Trump and Russia: A timeline of the investigation

Court filings say…