Meadows’ book is due to be released the same week he’s expected to appear before the Jan. 6 committee, following weeks of correspondence and hardball tactics that led Chair Bennie Thompson (D-Miss.) to threaten to hold Meadows in criminal contempt of Congress. But last week, Meadows’ lawyer George Terwilliger III and Thompson described a breakthrough, revealing that Meadows had provided thousands of emails to the panel and arranged to appear for an interview.

In the upcoming interview, committee members plan to challenge Meadows’ citing of executive privilege as a reason to avoid discussing his interactions with Trump. Now, they say, his book could become a factor in that argument.

In one excerpt of Meadows’ book, detailed Thursday by the Guardian, Meadows says Trump told him he was “speaking metaphorically” when he told supporters on Jan. 6 that he planned to march with them to the Capitol. Meadows writes that Trump “knew as well as anyone that we couldn’t organize a trip like that on such short notice.”

Some of the 700 Jan. 6 defendants have cited Trump’s promise to go with them to the Capitol as a reason they decided to go themselves. They joined a mob that ultimately overran police lines and breached the Capitol, injuring more than 140 officers and sending members of Congress fleeing for safety.

The select committee's chair indicated some of their questioning next week would relate to the book.

"I've seen excerpts from it. Some of what we plan to ask him is in the excerpts of the book," Thompson told reporters Thursday.

Lawmakers on the panel say Meadows’ decision to describe these interactions in his book could make it more difficult for him to refuse to discuss them in a congressional interview.

“You can’t assert a privilege that you have waived by virtue of your other actions,” said Rep. Jamie Raskin (D-Md.)

Asked about Meadows’ book describing Trump’s actions leading up to Jan. 6, Rep. Zoe Lofgren (D-Calif.) said, “If he did that, it’s a waiver legally.”

Thompson said the book might weaken Meadows' privilege claims, but it was ultimately up to him on how to respond to questions — or assert his Fifth Amendment rights.

"I think, obviously, anything in our group's opinion, is germane, but that's his prerogative to try to assert executive privilege or whatever," Thompson said when asked whether the book was relevant to Meadows' claims of privilege.

Whether Trump, as a former president, can seek to block his fromer aides from testifying at all is a dubious prospect, one that has found little cover in federal court. A district court judge recently rejected the notion that Trump could assert executive privilege to shield his former administration’s records from the Jan. 6 committee, emphasizing that the power to assert privilege belongs to the sitting president with rare, if any, exceptions. Trump has appealed that case and met a relatively icy reception from a three-judge appellate panel.

But even if Trump had authority to assert privilege, some legal experts say Meadows’ discussion of private interactions with Trump would likely weaken that claim.

“Executive privilege covers information vital to the national interest to protect, as well as the privacy of some internal White House deliberations. If the same information is made public, there can be no valid claim to a right to withhold it from Congress,” said Mark Rozell, a George Mason University professor and expert on executive privilege. “It is hard to imagine a stronger measure of contempt for Congress' authority than to refuse to cooperate with an investigation but being willing to present the requested information in the public domain to sell books.”

Heidi Kitrosser, a law professor from the University of Minnesota, said Meadow’s book “enhances the need for Congress to get the full story,” rather than just the details the Trump ally chose to put in a book. Rozell and Kitrosser have both signed legal briefs opposing Trump’s effort to shield his records from the Jan. 6 committee.

But Tim Flanigan, former White House deputy counsel to George W. Bush, said it’s a mistake to suggest that Meadows’ discussion of Trump in his book would permit him to reveal them to Congress if Trump continues to assert privilege. Rather, he said, a former president like Trump retains the authority to assert privilege — even if one of his allies discloses details meant to be confidential. Though principles like attorney-client privilege can be waived by inadvertent disclosures, Flanigan says executive privilege isn’t the same.

“The executive privilege is viewed differently because of the nature of the President's role, because of the need for other candor in the deliberations of the executive branch,” Flanigan said.

Meadows’ testimony is not the only legal conundrum facing the committee. At 10 a.m. Saturday, former Justice Department official Jeffrey Clark — a key ally in Trump’s effort to overturn the 2020 election — will return for a second deposition in person, at which he’s expected to assert his Fifth Amendment right to avoid self-incrimination. Panel members say they’ll determine whether they consider that assertion valid in deciding whether to ultimately hold Clark in contempt of Congress. The committee unanimously voted to hold Clark in contempt Wednesday night, but the measure would have to go through the full House before being referred to the Department of Justice.

Over 250 witnesses have come before the committee, its members have said.

“Trump appointees and administration officials to election officials in Arizona, in Michigan, Pennsylvania, Georgia, people who organized efforts to bring people to Washington on behalf of Stop the Steal, the campaign, the whole bit,” Thompson told reporters.

Lawmakers said that regardless of how the Clark deposition plays out, his acknowledgement that some of his actions could potentially cross the line into criminality is a breakthrough for their investigation.

“That he would be worried he’s committed a crime, which is what the Fifth Amendment is, is interesting, isn’t it,” said Lofgren.

“If you think about that,” said committee Vice Chair Liz Cheney (R-Wyo.), “in the context of the questions we're asking — which have to do with his discussions with President Trump about the election — and if he feels that he can't answer those questions about discussions with Donald Trump because he's worried that he could be facing criminal prosecution, the American people deserve to know that.”