Former FBI Director James Comey will stop short of saying President Trump interfered with the FBI's investigation into former national security adviser Mike Flynn when he testifies before the Senate Intelligence Committee on Thursday.

A source familiar with Comey's thinking told ABC News the former FBI director told those close to him he will not accuse Trump of obstructing justice. However, he will push back against the president's assertion that Comey told Trump three times he isn't under investigation.

"He is not going to Congress to make accusations about the president's intent, instead he's there to share his concerns," a source told ABC News.

Trump fired Comey last month, and it was later reported the president allegedly asked the former FBI director to end the investigation into Flynn.

The request concerned Comey, who reportedly memorialized that interaction, as well as others, in memos while he was at the FBI.

CNN reported last week Comey was planning to say in public testimony Trump pressured him to end the FBI's investigation into ties between Trump's campaign associates and Russia.

But the report was met with skepticism from some Republican lawmakers.

In an interview with CNN, Sen. Mike Lee, R-Utah, said he would be surprised if Comey said he was pressured, since he told a Senate panel that hadn't occurred.

"I'm on the Judiciary Committee, and just a few weeks ago, we had still-Director Comey come and testify," Lee said. "Someone asked him about political pressure, and he said this is something I haven't seen, and something in my experience has not occurred."

Comey was leading the investigation into Russian meddling in the 2016 election and ties between Trump campaign associates and Russian officials.

After Trump fired Comey, the Justice Department appointed former FBI Director Robert Mueller to oversee the investigation.

The Senate Intelligence Committee announced last week Comey would testify publicly Thursday at 10 a.m., and again in a closed session at 1 p.m.