Ronald Kessler, author of the upcoming The Trump White House: Changing the Rules of the Game, was interviewed Sunday by Jake Tapper on CNN’s State of the Union where he claimed that Donald Trump’s former campaign manager Kellyanne Conway was the White House’s “number one leaker.”

In his conversation with Tapper, Kessler said that his book had “juicy tidbits” from the White House and mentioned that during one interview with Conway, she forgot she was on the record and blasted her colleagues including former chief of staff Reince Priebus as well as Ivanka Trump and Jared Kushner. He added, “If you wonder why there are so many leaks out of the White House, one reason is Kellyanne Conway is the number one leaker.”

The book, which will be released on Tuesday, goes into detail about how Kushner and Ivanka Trump are “problems” in the administration. He writes that they have “no understanding of the basic fundamentals of how government works” and how they have no “understanding of the political consequences of their actions.” He also adds how the two had a hand in “the most disastrous and foolish decisions of Trump’s presidency” and how they were pushing Comey’s firing and Anthony Scaramucci’s hiring.