An indicted associate of Rudy Giuliani is offering to participate in Congress’s ongoing impeachment inquiry, although major legal hurdles remain before lawmakers’ seem likely to be able to tap the potential new source of information on President Donald Trump’s dealings with Ukraine.

Lev Parnas, a Ukrainian-born U.S. citizen currently under house arrest in Florida on campaign finance charges, is offering an olive branch to Congress after previously rebuffing a subpoena issued by the House Intelligence Committee last month.

“He will comply with a subpoena to testify as long as it doesn’t implicate some validly-held privilege of his,” said Joseph Bondy, a New York-based attorney for Parnas. “He’s not going to be held in contempt of Congress. He’s facing the subpoenas and will honor them to fullest extent possible. Where necessary, he may invoke the 5 ^th Amendment.”

“The bottom line is he’ll sit in the chair and he may invoke the privilege and maybe he will get immunity given that this is a matter of some import to national security,” Bondy added.

Bondy also said Parnas intends to comply with a subpoena for documents the House Intelligence Committee already issued.

Many of Parnas’ records were seized by the FBI in raids on his home and elsewhere around the time of his arrest last month at Dulles Airport near Washington as he prepared to board a flight to Vienna with his business partner, Igor Fruman, who was also arrested.

Last month, John Dowd, a former personal attorney for Trump, wrote to the panel on behalf of Parnas and Fruman saying they had not been given enough time to comply and warning that the records sought include information “protected by the attorney-client, attorney work-product and other privileges.”

“Other documents exist responsive to the subpoena,” Bondy said Monday. “To the extent we have materials responsive to the subpoena, they will be produced.”

Bondy said Parnas was “very upset” when Trump denied any association with him after word broke that he and Fruman were arrested.

“Imagine just the lay of the land: you give a bunch of money, you’re sitting with him at apparently intimate dinners, you’re seen waving at him at fundraisers and him waving back, you’re somehow recruited by Rudy Giuliani and after all that — spending a heck of a lot of money on Rudy Giuliani traveling or whatever — you’re sitting in a prison cell waiting to be bailed out and you learn the president has completely distanced himself from you. Of course, you’d be upset,” Bondy said.

Giuliani has not been charged in the criminal case, but he has acknowledged working with Parnas and Fruman to pursue the ouster of the U.S. ambassador to Ukraine and to jump start a long-dormant investigation that could impact Democratic presidential hopeful Joe Biden.

Prosecutors allege that Parnas and Fruman’s aggressive drive to oust the ambassador, Marie Yovanovitch, was mounted on behalf of at least one unnamed Ukrainian government official. The indictment also alleges that some of the hundreds of thousands of dollars in political donations the two men made were at the behest of an unnamed Russian businessman who wanted to start a U.S. marijuana business.

It’s unclear whether the complexities surrounding possible testimony from Parnas can be ironed out on a timetable that would allow him to speak to lawmakers when Democrats plan to hold open hearings later this month and potentially vote on articles of impeachment soon after that.

Granting immunity to a witness requires a two-thirds vote of a Congressional committee and is subject to a delay by the Justice Department. Lawmakers have been exceedingly reluctant to offer witnesses immunity since criminal cases against Lt. Col. Oliver North and John Poindexter were dismissed in the Iran-Contra affair in the wake of court rulings that cited their Congressional testimony.