Former National Security Adviser John Bolton's team was under fire from the White House and conservative commentators Sunday night, after a report in The New York Times revealed a bombshell excerpt from Bolton's forthcoming book that could prove pivotal in President Trump's impeachment trial -- just as the Amazon product page for the book went live.

The drama began earlier Sunday when the Times exclusively reported that Bolton's manuscript included a claim that Trump explicitly linked a hold on Ukraine aid to an investigation of Joe and Hunter Biden. Trump told Bolton in August, according to a transcript of Bolton's forthcoming book reviewed by the Times, "that he wanted to continue freezing $391 million in security assistance to Ukraine until officials there helped with investigations into Democrats including the Bidens."

The Times further claimed Bolton had shared a manuscript of his forthcoming book with "close associates" -- prompting Bolton's team to deny the claim, and assert that the National Security Council's [NSC's] review process of pending manuscripts is "corrupted" and prone to leaks.

A "pre-publication review" at the NSC, which functions as the White House's national security forum, is standard for any former government officials who held security clearances and publicly write or speak publicly about their official work. The review typically would focus on ferreting out any classified or sensitive material in advance of publication, and could take from days to months.

Trump fired back on Twitter on Sunday to refute Bolton's claims, saying he "NEVER told John Bolton that the aid to Ukraine was tied to investigations into Democrats, including the Bidens." Trump went on to accuse Bolton of trying to "sell a book," noting that Bolton did not complain publicly or privately about the aid holdup "at the time of his very public termination."

Other conservatives also suggested Sunday evening that Bolton's team may have leaked the information themselves while using the media as unwitting tools to juice their book sales. Online merchants began taking orders for Bolton's book, entitled "The Room Where It Happened," just as the Times' story broke, with a March release date.

"A former advisor to the President and the NY Times turned impeachment hearings into a marketing strategy and there are still people wandering around wondering how we ever ended up with Donald Trump," wrote podcast host Stephen Miller.

"Just like James Comey, John Bolton is trying to get rich off of a lie- and leak-fueled campaign to overturn the 2016 election results," wrote The Federalist's Sean Davis."I suspect it will work out as well as all of Bolton’s other wars."

Davis added, in a post that was retweeted by the president: "John Bolton is running the exact same revenge playbook against Trump that James Comey used. He’s even using the same agent and leaking to the same reporters. All because he’s mad Trump fired him for leaking and trying to start new wars. It’s so boring and predictable. ... If you think anyone other than Bolton’s lawyer, publisher, or agent leaked this to 1) juice sales of his book, and 2) get revenge against Trump for firing Bolton and refusing to start a bunch of new wars, you’re an idiot."

Meanwhile, CNN's Brian Stelter simply noted that Bolton's book was now on sale, with cover art that resembles the Oval Office.

Mused CBS News' "60 Minutes" correspondent John Dickerson, "Those publicists don’t miss a trick."

Sarah Tinsley, a senior adviser to Bolton, told Fox News he had submitted a hard copy draft of his manuscript to the NSC several weeks ago for "pre-publication review," but insisted he had not shared it with anyone else.

And, in a statement obtained by Fox News, Bolton attorney Charles Cooper lamented that the NSC review process had been "corrupted."

He also provided his letter to the White House concerning the manuscript.

READ BOLTON LAWYER'S INITIAL PREPUBLICATION REVIEW LETTER

"On December 30, 2019, I submitted, on behalf of Ambassador Bolton, a book manuscript to the National Security Council’s Records Management Division for standard prepublication security review for classified information. As explained in my cover letter to Ellen J. Knight, Senior Director of the Records Management Division, we submitted the manuscript notwithstanding our firm belief that the manuscript contained no information that could reasonably be considered classified and on the assurance that the 'process of reviewing submitted materials is restricted to those career government officials and employees regularly charged with responsibility for such reviews' and that the 'contents of Ambassador Bolton’s manuscript will not be reviewed or otherwise disclosed to any persons not regularly involved in that process.'"

Cooper continued: "A copy of my December 30 letter is attached. It is clear, regrettably, from The New York Times article published today that the prepublication review process has been corrupted and that information has been disclosed by persons other than those properly involved in reviewing the manuscript."

Bolton's team declined to "speculate" to Fox News as to how a description of his manuscript might have leaked to the Times. Additionally, Bolton's representatives made clear he was not denying the Times' claim concerning the Ukraine aid holdup and the possible investigation of the Bidens.

Bolton resigned last September, and Trump has said he was fired.

At a Fox News Town Hall with Chris Wallace on Sunday in downtown Des Moines, Iowa, Pete Buttigieg joined a chrous of Democrats in calling for Bolton to testify in the wake of the Times' report.

Bolton has said he'd be willing to testify if subpoenaed, and that he has relevant information.

"Just now, we're getting more indications about John Bolton, and what he knew, which is one more reason why, if this is a serious trial, we're going to have the witnesses and evidence," Buttigieg said.

The president has said that Bolton testimony might imperil national security and compromise executive privilege, the longstanding legal principle that generally protects executive branch deliberations from disclosure.

"The problem with John [Bolton] is, it's a national security problem," Trump told Fox News at a recent press conference in Davos, Switzerland. "If you think about it, he knows some of my thoughts, he knows what I think about leaders. What happens if he reveals what I think about a certain leader and it's not very positive? ... It's going to be very hard, it's going to make the job very hard. He knows other things. I don't know if we left on the best of terms. I would say probably not. So you don't like people testifying when they didn't leave on good terms -- and that was due to me, not due to him."

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Trump added: "The way I look at it, I call it national security. For national security reasons. Executive privilege, they say."

Trump's lawyers on Monday are set to resume presenting their defense in the Senate, which will then decide whether to hear additional witnesses by a simple majority vote. At the Town Hall, Buttigieg emphasized that Trump should be removed from office -- a highly unlikely eventuality, given that a two-thirds vote of the GOP-controlled Senate would be necessary.