Outgoing Utah Rep. Jason Chaffetz says he’s writing a book about the “deep state,” calling it “a monster unto itself.”

Chaffetz made the announcement on KSL Newsradio’s “The Doug Wright Show” and said he has unique experience with the entity as former chairman of the House Oversight and Government Reform Committee.

Supporters of President Donald Trump have alleged members of the so-called “deep state” are waging a war against the president.

Chaffetz’s resignation from Congress goes into effect Friday and comes the same week he announced he would become a Fox News contributor.

His first appearance on Fox News is scheduled for Saturday. Chaffetz said he will likely finish the book by the last part of 2018.