Former FBI Deputy Director Andrew McCabeAndrew George McCabeThe Mueller report concludes it was not needed Ten post-Mueller questions that could turn the tables on Russia collusion investigators Electronic surveillance isn't spying — it's much more powerful MORE accused President TrumpDonald John TrumpDemocrats' CNN town halls exposed an extreme agenda Buttigieg says he doubts Sanders can win general election Post-Mueller, Trump has a good story to tell for 2020 MORE of acting like a mob boss and releasing a “strain of insanity,” according to a copy of his new book obtained by The Guardian.

McCabe alleges in the book that Trump and White House Counsel Don McGahn offered him protection in exchange for loyalty.

“The president and his men were trying to work me the way a criminal brigade would operate,” he wrote.

McCabe became acting FBI director after Trump fired James ComeyJames Brien ComeyDavis: The shocking fact that Mueller never would have accused Trump of a crime Sarah Sanders is entitled to her opinions, but not her own facts James Comey, wife donated ,400 to Klobuchar's presidential campaign MORE. He also said in the book, "The Threat: How the FBI Protects America in the Age of Terror and Trump," that Trump directed Deputy Attorney General Rod RosensteinRod Jay RosensteinPoll: Majority says Barr's summary of Mueller report was 'largely accurate' Heavy lapses in judgment are politicizing the justice system Top Judiciary Republican reviews less-redacted Mueller report MORE to write a memo to justify the firing.

Rosenstein and the White House both publicly deny that Rosenstein was directed to write the memo, but, according to McCabe, Rosenstein privately said that Trump ordered him to write it.

“He said it wasn’t his idea. The president had ordered him to write the memo justifying the firing,” McCabe wrote.

Then-Attorney General Jeff SessionsJefferson (Jeff) Beauregard SessionsTrump poised to roll back transgender health protections Trump claims Mueller didn't speak to those 'closest' to him And the winner of the Robert Mueller Sweepstakes is — Vladimir Putin MORE fired McCabe last year after a Justice Department inspector general report found that he lied about media disclosures. He denied the allegation.

The book is expected to go on sale this month.