Michael Cohen fears Trump rhetoric could put his family at risk: Sources He has some reservations about his public testimony, sources said.

Michael Cohen is having reservations about his highly anticipated public appearance before Congress next month, fearing that President Donald Trump’s frequent diatribes against him could put his family in danger, according to sources close to Cohen.

While his testimony before the House Committee on Oversight and Reform appears to be on track to occur as scheduled on Feb. 7, it is now less certain than it initially appeared that Cohen -- Trump’s former attorney and fixer -- will sit before lawmakers, those sources told ABC News.

Cohen has become so worried that he is now questioning whether a public hearing is in his best interest, sources said, and people close to him have advised him to reconsider.

In an interview with FOX News on Saturday, Trump called Cohen “weak,” accused him of lying to prosecutors in order to get a reduced sentence, and hinted -- unprompted and without evidence -- that he possessed damaging information about Cohen’s family.

“[Cohen] should give information maybe on his father-in-law, because that’s the one that people want to look at,” Trump told FOX News host Jeanine Pirro. “That’s the money in the family.”

There has been no public indication during the investigation of Cohen that his father-in-law is or was the subject of any criminal inquiry.

“It’s an absolutely shocking violation of norms for the chief executive to suggest a retaliatory investigation against the relative of a witness against him,” said Kenneth White, a former federal prosecutor and criminal defense attorney with Brown, White & Osborn LLP. “This is Nixonian ‘enemy list’ stuff, but instead of the public finding out about it through secret tapes and insiders, the president is saying it openly on TV.”

Trump’s comments to FOX News also drew a swift rebuke from Maryland Democrat Elijah Cummings, the new chairman of the House Oversight Committee, who announced last week that Cohen had accepted an invitation to testify in public next month.

“The integrity of our process to serve as an independent check on the Executive Branch must be respected by everyone, including the President,” Cummings said in a statement released Sunday that was joined by Rep. Adam Schiff and Rep. Jerrold Nadler, the Democratic chairmen of the House Intelligence and Houses Judiciary Committees.

“Our nation’s laws prohibit efforts to discourage, intimidate, or otherwise pressure a witness not to provide testimony to Congress. The President should make no statement or take any action to obstruct Congress’ independent oversight and investigative efforts, including by seeking to discourage any witness from testifying in response to a duly authorized request from Congress,” the statement said.

The White House did not immediately respond to a request for comment.

Congressional leaders have been helpful and accommodating to Cohen’s concerns, sources told ABC News, and Cohen still wants to testify, but the president’s recent comments are not the first time he has gone after Cohen and his family.

After Cohen accused the president in court of directing him to arrange hush money payments to two women during the presidential campaign, the president used his Twitter account – which has 57 million followers – to accuse Cohen of lying and to suggest that Cohen should “serve a full and complete sentence.”

One day after Cohen was sentenced to three years in prison, Trump tweeted that Cohen agreed to plead guilty only “to embarrass the president and get a much reduced prison sentence, which he did – including the fact that his family was temporarily let off the hook.”

And late last year, Trump called Cohen a “rat” for cooperating with federal prosecutors.

In an exclusive interview with ABC News Chief Anchor George Stephanopoulos last month, Cohen fired back at the president’s remarks.

“I did not do it to embarrass the president. He knows the truth. I know the truth, many people know the truth,” Cohen said. “Under no circumstances do I want to embarrass the president of the United States of America. The truth is, I told the truth. I took responsibility for my actions. And instead of him taking responsibility for his actions, what does he do? He attacks my family.”

ABC News’ Lauren Pearle contributed to this report.