A new book about the Trump White House indicates that the president's former campaign manager is eyeing the top job.

According to author Michael Wolff's Fire and Fury: Inside the Trump White House, Steve Bannon has told people there's a 33.3 percent chance that his former boss, Donald Trump, will be impeached as a result of the investigation by special counsel Robert Mueller.

Bannon also reportedly said there is a 33.3 percent chance that Trump will resign, "perhaps in the wake of a threat by the cabinet to act on the Twenty-Fifth Amendment (by which the cabinet can remove the president in the event of his incapacitation)."

Bannon has also allegedly said there's a 33.3 percent chance that Trump "would limp to the end of his term" but wouldn't seek reelection.

"Less volubly, Bannon was telling people something else: he, Steve Bannon, was going to run for president in 2020," Wolff adds in his book.

That was suggested by Bannon's language, which changed from "if I were president" to "when I am president".

"The top Trump donors from 2016 were in his camp, Bannon claimed: Sheldon Adelson, the Mercers, Bernie Marcus, and Peter Thiel," Wolff writes.

The Guardian newspaper has quoted a former chief White House ethics lawyer, Richard Painter, speculating that Bannon might be cooperating with Mueller.

“He has no incentive to cover up for Trump, or his family members,” Painter said.

Since Bannon's disparaging comments about Trump have been reported—including the statement that the president "has lost it"—the former chief strategist is himself facing opposition from former friends and supporters.

CBS News has reported that Breitbart News Network's board of directors "is considering ousting" him as the executive chairman.

A member of the billionaire Mercer family has also disavowed Bannon.

"I support President Trump and the platform upon which he was elected," Rebekah Mercer said in a statement published in the Washington Post. "My family and I have not communicated with Steve Bannon in many months and have provided no financial support to his political agenda, nor do we support his recent actions and statements."

Trump declared on his Twitter feed that "sloppy Steve Bannon" has been dumped by the Mercers.

https://twitter.com/realDonaldTrump/status/949303089416294401

Fire and Fury also suggests that Trump's daughter Ivanka is eyeing the presidency.

"Jared and Ivanka had made an earnest deal between themselves: if sometime in the future the time came, she'd be the one to run for president (or the first one of them to take the shot)," Wolff writes. "The first woman president, Ivanka entertained, would not be Hillary Clinton, it would be Ivanka Trump."

Bannon was "horrified" when this was reported to him.

"Please don't tell me that," Bannon said, according to the book. "Oh my god."