Steve Bannon expected to meet with House Intel Committee

— -- Former White House chief strategist Stephen Bannon is expected to meet behind closed doors with the House Intelligence Committee Tuesday, a congressional source and two sources close to Bannon tell ABC News.

Bannon will field questions from congressional Russia investigators for the first time as he continues to face backlash for his comments in a controversial new book about the Trump White House by author Michael Wolff that has renewed questions about the president's mental fitness and campaign activity.

Bannon, who joined the Trump campaign in August of 2016, said the controversial June 2016 Trump Tower meeting between campaign officials and a Russian lawyer thought to have dirt on Hillary Clinton was "treasonous," according to "Fire and Fury: Inside the Trump White House."

"The three senior guys in the campaign thought it was a good idea to meet with a foreign government inside Trump Tower in the conference room on the 25th floor – with no lawyers," Bannon said, according to Wolff. "Even if you thought that this was not treasonous, or unpatriotic ... you should have called the FBI immediately."

In the book, he also suggested Special Counsel Robert Mueller's investigation would focus on money laundering - something the panel has spent time investigating abroad.

Bannon, who stepped down as executive chairman of Breitbart News last week amid the fallout over his comments, has since regretted his comments in the book and has called Donald Trump Jr., one of the campaign officials who participated in the meeting, a "patriot and a good man."

Rep. Adam Schiff, D-Calif., the top Democrat on the House Intelligence Committee, said the panel has questions about Bannon's comments in the book - including his suggestion that Trump Jr. brought the participants to meet with then-candidate Donald Trump.

“Specifically what's the basis for his assertion that the president met with the participants in the Trump Tower meeting,” Schiff said in an interview with ABC News' Pierre Thomas. “What [Bannon] knows about the president’s knowledge of that meeting, as well as his concerns over money laundering which has been a persistent concern of ours as well.”

The committee first reached out to Bannon with a request for documents and an interview before the release of "Fire and Fury." Trump's former political adviser is also expected to face questions about his knowledge of Russian contacts during the transition.

“We know from the Erik Prince testimony…that [Prince] had a meeting with Steve Bannon before he made that trip to the Seychelles traveling halfway around the world to have what he described essentially as a coincidental meeting with a Russian in a bar,” Schiff said. “Which just happened to be a head of one of the Russian Investment Banks, so we'd like to know whether Steve Bannon was involved in establishing any kind of a back channel of with the Russians.”

Bannon isn't the only Trump associate expected before the committee this week: Corey Lewandowski, Trump's first presidential campaign manager, is expected before the panel later this week.

"I have nothing to hide. I didn't collude or cooperate or coordinate with any Russian, Russian agency, Russian government or anybody else, to try and impact this election," he told WABC Radio's Rita Cosby in a recent interview.

Bannon's interview comes as the Senate Intelligence and Judiciary committees continue their investigations into allegations of collusion between the Trump campaign and Russia.

Republicans on the Senate Judiciary Committee, along with the House Judiciary and Oversight committees, are also seeking interviews with Justice Department officials involved with the Hillary Clinton email investigation and initial Russia probe.

So far there is no indication that Bannon is being investigated by the Special Counsel Mueller.