She said that President Bush was told of some of the excerpts but would not be commenting on them because “he has more pressing matters than to spend time commenting on books by former staffers.” But Karl Rove, a principal target of many of Mr. McClellan’s charges and the former deputy chief of staff for President Bush, reacted immediately on Tuesday night. Speaking on Fox News, where he is now a commentator, Mr. Rove said Mr. McClellan was not even present at many of the meetings he describes and suggested that he was not writing truthfully.

“First of all, this doesn’t sound like Scott. It really doesn’t,” he said. “Not the Scott McClellan I’ve known for a long time. Second of all, it sounds like somebody else. It sounds like a left-wing blogger.

“If he had these moral qualms,” he added, “he should have spoken up about them.”

Mr. McClellan’s book, “What Happened: Inside the Bush White House and Washington’s Culture of Deception,” is the first negative account by a member of the tight circle of Texans around Mr. Bush. Mr. McClellan, 40, went to work for Mr. Bush when he was governor of Texas and was the White House press secretary from 2003 to 2006.

The revelations in the book, to be published by PublicAffairs next Monday, were first reported Tuesday on Politico.com by Mike Allen. Mr. Allen wrote that he bought the book at a Washington store. The New York Times also obtained an advance copy.

Image Scott McClellan Credit... Doug Mills/The New York Times

Mr. McClellan writes that top White House officials deceived him about the administration’s involvement in the leaking of the identity of a C.I.A. operative, Valerie Wilson. He says he did not know for almost two years that his statements from the press room that Karl Rove and I. Lewis Libby Jr. were not involved in the leak were a lie.