(CNN)Michael Cohen, President Donald Trump’s former personal attorney, claims that then-candidate Trump knew in advance about the June 2016 meeting in Trump Tower in which Russians were expected to offer his campaign dirt on Hillary Clinton, sources with knowledge tell CNN. Cohen is willing to make that assertion to special counsel Robert Mueller, the sources said.
Cohen alleges that he was present, along with several others, when Trump was informed of the Russians’ offer by Trump Jr. By Cohen’s account, Trump approved going ahead with the meeting with the Russians, according to sources.
To be clear, these sources said Cohen does not have evidence, such as audio recordings, to corroborate his claim, but he is willing to attest to his account.
Contacted by CNN, one of Cohen’s attorneys, Lanny Davis, declined to comment.
“He’s been lying all week, he’s been lying for years,” said Rudy Giuliani, the President’s attorney, to Chris Cuomo on CNN’s “Cuomo Prime Time” on Thursday night.
He added, “I don’t see how he’s got any credibility.”
Giuliani also said Cohen is “the kind of witness that can really destroy your whole case” and called Cohen, who was a top Trump Organization attorney for a decade, a “pathological liar.”
“Donald Trump Jr. has been professional and responsible throughout the Mueller and Congressional investigations,” said Alan Futerfas, an attorney for Donald Trump Jr. “We are very confident of the accuracy and reliability of the information that has been provided by Mr. Trump, Jr., and on his behalf.”
According to people who have discussed the matter with Cohen, he has expressed hope that this claim about the Trump Tower meeting will help him reach out to Mueller and possibly lessen his legal troubles. He’s under scrutiny by federal prosecutors in Manhattan after Mueller referred Cohen’s case to them.

At the meeting, Trump Jr. was joined by his brother-in-law Jared Kushner and Paul Manafort, who was Trump’s campaign chairman at the time. There were four Russians in the room, including a lawyer with Kremlin ties, a businessman who worked for an oligarch and a lobbyist with old KGB connections.
After news of the meeting broke in July 2017, the Trump team offered misleading explanations and changed their story several times. But one claim stayed consistent: that Trump had no knowledge of the meeting beforehand, wasn’t told about it afterward and first learned about it one year later.
Those denials were repeatedly issued by Trump, his attorney Jay Sekulow, Trump Jr., Futerfas and White House press secretary Sarah Sanders. Those people denied that Trump had contemporaneous knowledge of the meeting on more than 15 occasions, according to CNN’s analysis.

Trump said on July 12, 2017, that he “only heard about it two or three days ago.” One week later, Trump repeated that he “didn’t know anything about the meeting” because “nobody told me” about it.
Around that same time, CNN’s Jake Tapper asked Sekulow to confirm Trump’s claims that he only recently learned about the controversial meeting. Sekulow’s response: “Yes, I swear.”
But perhaps the highest-stakes denial was given by Trump Jr. in his testimony last year to the Senate Judiciary Committee.
“He wasn’t aware of it,” Trump Jr. told lawmakers, referring to his father’s knowledge of the meeting. “And, frankly, by the time anyone was aware of it, which was summer of this year, as I stated earlier, I wouldn’t have wanted to get him involved in it because it had nothing to do with him.”

Even Steve Bannon, the former White House chief strategist and top Trump campaign official, said the meeting was “treasonous” and speculated that “the chance that Don Jr. did not walk these (Russians) up to his father’s office on the twenty-sixth floor is zero.” Trump Jr. has denied Bannon’s allegation. Bannon’s comments, to author Michael Wolff for his book “Fire and Fury,” triggered the bitter public divorce between Bannon and Trump in early 2018.
Update: This story has been updated with more comments by Rudy Giuliani.