(CNN) Omarosa Manigault Newman entered the White House as one of President Donald Trump's longest-serving associates, the only person aside from his daughter who'd known and worked alongside him for more than a decade. She was given an office, an assistant and the highest salary afforded an administration staffer.

Those days, she announces with flourish in a new memoir , are over.

Her dramatic divorce from a man she likens to a cult leader is the subject of a salacious, self-serving, mostly unverifiable account of her West Wing tenure, "Unhinged: An Insiders Account of the Trump White House" (Gallery Books, 330 pages). Early excerpts have been denounced by White House officials, who are launching a concerted effort to discredit their former colleague. Asked about his former friend and aide on Saturday, Trump was frank.

"Low-life," he declared during a rain-soaked photo-op with motorcyclists at his New Jersey golf club. "A low-life."

The book is due to be released next week, but CNN obtained a copy on Friday.

In it, Manigault Newman describes a mentally waning, racist and lewd, charismatic but emotionally abusive, man overseeing a conniving cast of aides and family members whose varied goals rarely include the betterment of the nation.

Manigault Newman was previously best known for her polarizing character on NBC's "The Apprentice."

She insists her firing last December was because she knew too much about a possible audio recording of the President uttering a racial epithet, which she claims was the subject of deep consternation among campaign — and later White House — aides. Manigault Newman provides no proof of the alleged recording. She writes she turned down an offer from Trump's daughter-in-law to sign a nondisclosure agreement in exchange for a job on the President's re-election campaign paying $15,000 per month. The book did not include a copy of the nondisclosure agreement, but The Washington Post said it reviewed it . The campaign declined CNN's request for comment.

Manigault Newman, who was in charge of Trump's African-American outreach, also recounts instances that made her re-think her loyalties to the President and the administration, particularly in the wake of the white supremacist rally in Charlottesville in August 2017.

"Donald Trump, who would attack civil rights icons and professional athletes, who would go after grieving black widows, who would say there were good people on both sides, who endorsed an accused child molester; Donald Trump, and his decisions and his behavior, was harming the country. I could no longer be a part of this madness," she wrote.

Manigault Newman, however, remained employed at the White House for several months after the deadly Charlottesville rally and did not leave voluntarily. Her book, and the account it provides of a President who stokes racial tensions for political purposes, comes about one-year after the rally

But there are very few particulars that can be verified in her book; many are clearly wrong, such as an inaccurate account of what Trump said during remarks on his second day in office at CIA headquarters in Langley, Virginia.

Quoting Trump's early, post-inauguration speech at the CIA lamenting his inauguration crowd, Manigault Newman takes some editorial liberty, adding within quotation marks that Trump says, "Liars! Fake news!" He did not say that.

Others are being denied by the White House, some more forcefully than others; a description about the drama of installing a tanning bed in the White House residence is untrue, officials insisted, claiming there is no such apparatus in Trump's home.

Other details Manigault Newman passes off as her own original observations, even if they were reported on months or even years ago, like the inability of Trump staffers to turn on the lights during meetings early in the administration.

On Friday, as excerpts from Manigault Newman's book emerged, the White House decried the author and the media for offering her their attention. Press secretary Sarah Sanders, who was on vacation, wrote the book is "riddled with lies and false accusations."

"It's sad that a disgruntled former White House employee is trying to profit off these false attacks, and even worse that the media would now give her a platform, after not taking her seriously when she had only positive things to say about the President during her time in the administration," Sanders wrote.

The memoir features Manigault Newman describing having witnessed disturbing scenes of the President making lascivious comments about his own daughter Ivanka, who Manigault Newman alleges "uses his obsession with her to her advantage." Meantime, Trump is quoted dismissing his eldest son Donald Trump Jr. as a "f**k up."

And she compares the President's mind to a dull blade, suggesting he no longer pronounces long words correctly and has trouble recollecting his rationale for major decisions, including firing FBI Director James Comey. The deterioration, she posits, is perhaps due to his copious intake of Diet Coke.

A recurring subplot is Manigault Newman's enmity toward chief of staff John Kelly , who she accuses of "locking" her in the basement Situation Room in order to fire her on dubious grounds (she was accused of misusing the White House car service). In his bid to bring order to a fractious West Wing, Kelly had earlier imposed stricter rules about who had access to the President, a move that senior officials said limited Manigault Newman's time in the Oval Office.

Still, as the White House aide who had one of the longest relationships with the President, Manigault Newman enjoyed rare stature, at least at moments. She was a contestant on the first season of NBC's "The Apprentice," and later worked on Trump's presidential campaign. Her paycheck was among the largest in the building, according to public records, and she remained a highly visible face of the administration.

In her book, Manigault Newman attempts to explain why she remained at his side, even as he took steps that angered her.

"Donald Trump was uncannily intuitive and extremely perceptive. He seemed to be able to sense when certain individuals were susceptible to being influenced by his power and abiding by his loyalty demands," she writes, explaining Trump's pull.

The offer of money and a job in exchange for signing a non-disclosure agreement, however, raised Manigault Newman's hackles.

"Treating someone with love and kindness after abuse is a classic cult tactic," she wrote. "I felt myself being manipulated, but refused to allow that to happen."

White House aides aim to push back against Manigault Newman by going after her credibility and disputing parts of the book they perceive as unfair, said a White House official who would not go on the record. The official said their approach would be similar to their response to Michael Wolff's "Fire and Fury" roll out. Then, officials attacked Wolff's reputation, claimed specific people had been misquoted and sent aides and surrogates on shows to trash the book.

This official says the White House doesn't know everything the former staffer has claimed because it appears they have not seen a copy of the book.

But in the battle of credibility between a scorned staffer and an administration that routinely lies, few winners emerge.

"This White House has a problem with the truth," Manigault Newman writes, seeming to pre-empt the pushback the West Wing launched even before the publication date. "But at least they are consistent -- and only too predictable -- with the lies they tell."