Jan. 6 committee members on Thursday told Politico that former White House chief of staff Mark Meadows may have poked holes in his argument for withholding his contacts with former President Trump on the day of the deadly Capitol insurrection by revealing selected details in his book set to be released next week.

“It’s … very possible that by discussing the events of Jan. 6 in his book, if he does that, he’s waiving any claim of privilege. So, it’d be very difficult for him to maintain ‘I can’t speak about events to you, but I can speak about them in my book,’” Rep. Adam Schiff (D-CA), one of the panel’s nine members, told Politico.

Schiff’s remarks comes days after Meadows began to engage with the committee through his attorney after initially defying the panel’s subpoena, which the panel warned could land him a referral for criminal contempt if he didn’t comply this week.

On Tuesday, chair Rep. Bennie Thompson (D-MS) confirmed that Meadows’ attorney, George Terwilliger, has provided records to the committee and that Meadows would soon appear for an initial deposition.

Meadows’ book release on Tuesday will occur the same week that he is expected to appear before the committee.

Committee members are reportedly planning to challenge Meadows’ claim of executive privilege as his rationale for avoiding disclosures of his interactions with the former president. Members now note that Meadows’ book could become a factor in assessing the validity of that argument.

In an excerpt of the book obtained by The Guardian, Meadows claimed 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 wrote that the former president “knew as well as anyone that we couldn’t organize a trip like that on such short notice.”

Some of the 700 insurrectionists have pointed to Trump’s vow to march with them to the Capitol in explaining why they decided to go there on Jan. 6 and ultimately join the mob of Trump supporters who breached the Capitol.

Committee members argue that Meadows’ decision to detail that type of exchange with Trump in his book could pose more obstacles for him in refusing to discuss them during a congressional interview.

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

Rep. Zoe Lofgren (D-CA) also told Politico that she thinks “it’s a waiver legally” if Meadows details Trump’s actions leading up to the Capitol insurrection.

For months, Trump’s lawyers have been arguing in court that the former president should be allowed to assert executive privilege over records from the committee. Trump’s lawyers took those arguments to a federal appeals court Tuesday after losing in district court last month.