Bill Barr, who served as US Attorney General under Donald Trump, has described the former president as a “narcissist’ and urged the Republican party not to back him in 2024, in a blistering assessment for his tell-all book.

Mr Barr, a once-close ally of Mr Trump speaking publicly for the first time since leaving office, claims it was the president’s “self-indulgence and lack of self-control,” that lost him the 2020 election.

In the book, “One Damn Thing After Another,” Mr Barr says the 75-year-old businessman “has shown he has neither the temperament nor persuasive powers to provide the kind of positive leadership that is needed.”

Mr Barr, who resigned in December 2020 following a falling out with the president, takes a decidedly dim view of Mr Trump after working closely together for much of the final two years of his time in office.

He thinks Mr Trump could have beaten Joe Biden in 2020 if he had “just exercised a modicum of self-restraint, moderating even a little of his pettiness.”

“Trump cared only about one thing: himself. Country and principle took second place,” he writes in his 600-page book, which is out on March 8. The Washington Post, New York Times and several other publications have seen shared copies before its release.

“Donald Trump has shown he has neither the temperament nor persuasive powers to provide the kind of positive leadership that is needed,” he goes on.