Within minutes of his firing in May, former FBI Director James Comey received a call from John Kelly, then the head of the Department of Homeland Security and now the White House chief of staff.

According to Comey’s account, which is set to appear in his highly anticipated forthcoming memoir, Kelly was “emotional” over the manner in which Comey was let go. The then-FBI director was in California at the time, speaking to FBI agents in Los Angeles, and only found out that he was out of a job when he saw the news break on TV.

Kelly, Comey recalls, said he was “sick” about the situation and “intended to quit” in protest. Kelly “said he didn’t want to work for dishonorable people,” referring specifically to President Donald Trump, who appeared to be upset at the FBI’s persistent investigation into his campaign’s possible collusion with Russian officials.

According to sources, Comey writes in his book that he encouraged Kelly to remain in his post, saying “this president,” more than his predecessors, needed people of principle and integrity around him.

The phone call was first reported by CNN last year. But Comey’s book provides both on the record confirmation and additional details of the conversation. Those details were relayed to The Daily Beast by two sources who have read the book, A Higher Loyalty, prior to its planned release on Tuesday.

The revelations conveyed by Comey threaten to cause a firestorm within the White House, further complicating an already tenuous relationship between Kelly and Trump. The chief of staff has been on increasingly thin ice with the president in recent weeks, largely dating back to his disastrous handling of the resignation of Rob Porter, a former White House official accused of beating his former wives. Kelly reportedly told Trump in February that he would resign if asked. And Trump has let it be known to numerous aides and confidants that he feels comfortable operating around (and even without) his chief of staff.

“ The revelations conveyed by Comey threaten to cause a firestorm within the White House, further complicating an already tenuous relationship between Kelly and Trump. ”

A senior White House official disputed Comey’s characterization of the phone call with Kelly, saying that Kelly has maintained that the call was brief—roughly a minute long—and that the gist was, “I don’t know why you got fired, [and] best of luck to you,” according to the official. The version of this story that Kelly has told other senior staffers clashes markedly with Comey’s, the official noted, and does not include Kelly calling President Trump “dishonorable.”

Comey appears to be pulling no punches in either his book or in sit-downs promoting it. According to Axios, he compared Trump to a mob boss in an interview with ABC News’ George Stephanopoulos slated to air on Sunday. One of the sources who described Comey’s account of Kelly’s phone call said the former FBI director’s book is filled with anecdotes that will potentially upset a president already seething over the persistence of the investigation into Russian election-meddling that Comey once led. The recounting of Kelly’s phone call, the source said, “reflects a larger theme of the book and the Trump administration—how hard it is for ethical people to stay in close proximity to bullies who lack integrity and honor.”

Anticipating an unfriendly portrayal, White House allies are ramping up a counteroffensive designed to push back on the book and Comey’s accompanying media tour. The Republican National Committee has taken the lead in the effort.

The Trump White House is not amassing an official rapid-response operation, reportedly due to internal concerns that the president would quickly undermine official talking points by directly responding to Comey’s claims and public utterances. But White House officials told The Daily Beast that their strategy regarding the book and the Comey tour will be largely shaped in real-time, forming and adjusting to accommodate however publicly and furiously Trump reacts.

“What’s dishonorable is that James Comey lied about leaking information to the media, consistently contradicted himself in testimony, and made a series of bizarre decisions as FBI director,” RNC spokesman Michael Ahrens told The Daily Beast on Thursday morning. “That’s why Republicans and Democrats alike have said he has no credibility.”

Loyalists and associates of Hillary Clinton, the 2016 Democratic presidential nominee who has her own rocky history with Comey, are also doing their part to push back on what they expect will be a poor portrayal of the former secretary of state. Some confidants are demanding concessions that Comey is unlikely to make.

“Mr. Comey needs to put his big-boy pants on, admit that his unethical action swung the election to Trump, and beg for forgiveness,” former Clinton strategist Paul Begala told The Daily Beast earlier this week.

Comey is expected to directly address controversies involving both Trump and Clinton, but the book also covers other contentious moments of the veteran law enforcement officer’s career, The Daily Beast is told. They include his dramatic battles with the Bush administration over a controversial surveillance program and high-profile prosecutions ranging from the Italian mob to Martha Stewart.