Joe Biden’s aides fight back in a new book that accused the White House of inner circles of covering up the “physical deterioration” of the former U.S. president during his poorly-fated re-election campaign.

According to the book, Biden's situation in the 2024 presidential campaign was so poor that his aides discussed putting him in a wheelchair.

A spokesman for Biden, 82, said "evidence of aging is not evidence of mental incapacity" and that keeping Democrats "a very effective president."

Written by CNN's Jake Tapper and Alex Thompson of Axios, the book will be released on May 20.

Biden abruptly ended his re-election campaign last July shortly after a disastrous debate performance with Republican Donald Trump.

Party insiders accused him of being too late, and his replacement vice president Kamala Harris left for 107 days to challenge Trump who swept the victory.

Before the book was released, Biden had his first interview last week since leaving the White House for the BBC, saying: “If he had left the game early, I don’t think it would be important.”

Although the book largely cites anonymous sources from interviews with more than 200 people, one of the few quoted in the record is David Plouffe, who runs the campaign of Vice Chairman Harris.

The book quotes Plov as saying: "We were screwed up by Biden."

The author wrote: “Biden’s physical deterioration – most obviously in his stop walking – has become so severe that internal discussions put the president in a wheelchair, but they can’t do it until after the election.

The book adds: “Given Biden’s age, he (his physician Kevin O’Connor) also said privately that if he falls again, a wheelchair may be necessary for a difficult recovery.”

Biden's physical condition has been greatly reduced, and assistants have tried to make sure he walks shorter, use handrails when installing stairs, and wear trainers more frequently.

At the time, Biden's aide repeatedly told reporters that his gait change was due to a fracture of his foot in November 2020, and he later refused to always wear his prescription surgical boots.

In a statement to Axios, an anonymous Biden aide said: "Yes, physical changes have changed as they age, but the evidence of aging is not evidence of mental incompetence."

The spokesman added: “We are still waiting for someone, anyone, to point out where Joe Biden has to make a presidential decision or make a president’s address because of the psychological decline, he can’t do his job.

“In fact, the evidence shows that the contrary – he is a very effective president.”

Tapper and Thompson's book also said Biden did not endorse George Clooney in a star-studded California campaign fundraiser hosted by Hollywood stars last June.

"Thank you for being here," Biden told Clooney at the event, apparently he wasn't aware that he was speaking to the Academy Award winner.

According to reports, an aide told Biden that he had worked hard to train Clooney as he said: "You know George."

Shortly after the incident, Clooney wrote an article in the New York Times calling on Biden to withdraw from the game. The actor was one of the first major donors to publicly withdraw support.

The book also claims that Biden forgot the names of senior aides, including trusted loyalist Mike Doniron, national security adviser Jack Sullivan and White House communications director Kate Bedingfield.