A lawyer for U.S. President Donald Trump sought Thursday to block publication next week of a book recounting insider recollections of Trump's chaotic first year in the White House, contending that it is defamatory and libelous. Attorney Charles Harder demanded in a letter to author Michael Wolff and his publisher, Henry Holt and Co., that they stop Tuesday's scheduled release of Wolff's book, Fire and Fury: Inside the Trump White House. Harder said his team is "investigating numerous false and/or baseless statements" made about Trump in the book that Wolff said came from more than 200 interviews he conducted during Trump's successful 2016 election campaign and after the president took office a year ago. Early excerpts published Wednesday provoked a firestorm in official Washington. Within hours, Harder sent a cease-and-desist letter to Trump's former chief strategist, Steve Bannon, who is quoted extensively in the book, demanding that he stop making defamatory remarks about Trump and his family. Trump was described by his spokeswoman Sarah Sanders as "furious and disgusted" by Bannon's remarks. She told reporters Thursday that the book is "complete fantasy…tabloid gossip." In the most controversial comment, Bannon was quoted as saying that he thought it was "treasonous" and "unpatriotic" that Trump's eldest son, Donald Trump, Jr., along with the president's son-in-law, Jared Kushner, now a White House adviser, and then-campaign manager Paul Manafort, met with Russians in the midst of the campaign at Trump Tower in New York. The younger Trump had been promised by an intermediary for the Russians that he would be handed incriminating documents about Trump's election challenger, Democrat Hillary Clinton, as part of Moscow's effort to help Trump win, although Trump, Jr. subsequently said no such damaging evidence materialized. Within hours of the book excerpt surfacing, Trump said in a statement, "Steve Bannon has nothing to do with me or my presidency. When he was fired, he not only lost his job, he lost his mind." Trump said that Bannon was "only in it for himself" and "spent his time at the White House leaking false information to the media to make himself seem far more important than he was" at the same time that he had declared war on the media. Despite Trump's rebuke, Bannon, chief executive of Trump's campaign in the last three months before the November 2016 election, on Wednesday night described the president as "a great man." Bannon told a questioner on a radio show, "You know I support him day in and day out." Bannon said that "nothing will ever come between us and President Trump and his agenda." On Thursday, Trump said, "He called me a great man last night, so he obviously changed his tune pretty quick." In the book, Bannon is quoted as saying, "Even if you thought that (the June 2016 Trump Tower meeting) was not treasonous, or unpatriotic, or bad s—, and I happen to think it's all of that, you should have called the FBI immediately," referring to the top U.S. law enforcement agency, the Federal Bureau of Investigation. Press secretary Sanders told reporters Wednesday it is a "ridiculous accusation" that the president's son committed treason. Bannon is also quoted as saying that Trump, Jr. will "crack like an egg" under the pressure of the investigations into meddling by Russia in the last U.S. presidential election. Sanders said author Wolff wrote "false and misleading accounts from individuals who have no access or influence with the White House," but she acknowledged the author was allowed to have "dozens of interactions" at the White House since Trump became president. After leaving the White House, Bannon remained a staunch Trump supporter, but has failed so far in his political efforts to help insurgent Republican candidates win congressional seats to support Trump's populist agenda. "You have a former adviser here who has almost as big as an ego as the president himself," says presidential historian David Cohen. Focus on money laundering According to the book, Bannon says the investigative team led by special counsel Robert Mueller, now in the midst of a criminal investigation of alleged Trump campaign collusion with Russia during the election, is focusing on money laundering. "Their path to f—— Trump goes right through Paul Manafort, Don, Jr. and Jared Kushner," Bannon is quoted saying. "It's as plain as a hair on your face." The rupture with the Trump White House makes Bannon a potentially dangerous adversary as he was present at many critical meetings during the campaign and in the White House. "He knows where the bodies are buried," Cohen, a political science professor at the University of Akron (Ohio), told VOA. "If Bannon is publicly breaking with Trump, who's to say he's not going to potentially tell all to the investigators? This could be extremely damaging from a legal perspective to Trump." Mueller has already indicted Manafort and another Trump campaign aide, Rick Gates, on money laundering charges linked to their lobbying efforts for Ukraine prior to the 2016 election, and secured guilty pleas from former national security adviser Michael Flynn and former foreign policy adviser George Papadopoulos for lying to federal agents about their Russia contacts. Aside from probing Trump campaign links with Russia, Mueller is also looking into whether Trump obstructed justice by firing former FBI Director James Comey, who was heading the agency's Russia investigation before Mueller was appointed to take over the probe. Manafort, in an unusual legal move, on Wednesday sued Mueller. The civil lawsuit accuses Deputy Attorney General Rod Rosenstein, who appointed Mueller, of exceeding his legal authority to "grant Mr. Mueller carte blanche to investigate and pursue criminal charges in connection with anything he stumbles across." "The lawsuit is frivolous, but the defendant is entitled to file whatever he wants," a Justice Department spokesperson said.