President Donald Trump is going to war against Michael Wolff’s book, sending a cease and desist letter to his publisher.

The letter demands that Wolff apologize to Donald Trump for “defamatory statements” and demanding that they not publish the book.

NEW this am: Trump attorneys send cease-and-desist letter this morning to Wolff and book publisher @HenryHolt demanding they stop publication and issue an apology to @realDonaldTrump for defamatory statements made thus far. — Carol Leonnig (@CarolLeonnig) January 4, 2018

Trump’s lawyers also sent a cease and desist letter to his former aide Steve Bannon, complaining that he had breached his non-disclosure agreement.

The letter read:

On behalf of our clients, legal notice was issued today to Stephen K. Bannon, that his actions of communicating with author Michael Wolff regarding an upcoming book give rise to numerous legal claims including defamation by libel and slander, and breach of his written confidentiality and non-disparagement agreement with our clients. Legal action is imminent.

But according to Axios, Wolff spent a lot of time with Trump officials in and out of the West Wing, including with Bannon, White House chief of staff Reince Priebus and his deputy Katie Walsh. The book was sanctioned by the White House, although Trump aides are blaming Bannon for enabling Wolff.

Wolff has dozens of hours of recorded conversations with Trump officials even though many of them thought they were off the record.