William Barr, Donald Trump’s former attorney general, said in an interview on Thursday that it would be a “big mistake” for the Republican party to nominate Trump for president in 2024.

Appearing on the Newsmax television channel, Barr said Trump, who has hinted that he will run again, would not be a sound choice.

“I don’t think he should be our nominee – the Republican party nominee,” Barr said.

“And I think Republicans have a big opportunity – it would be a big mistake to put him forward.”

In a poll in January 57% of Republican voters said they would choose Trump in 2024. Trump also won the less scientific Conservative Political Action Conference straw poll, in February, by a large margin.

Trump, who was impeached twice during his four years in the White House, has repeatedly teased his supporters with suggestions he will run again.

“We did it twice, and we’ll do it again,” Trump told a crowd at the CPAC convention – claiming again that he won the 2020 election.

“We’re going to be doing it again a third time.”

Still, Barr’s remarks will be sure to anger Trump, who has repeatedly clashed with his former attorney general since losing the 2020 election.

In Barr’s book, One Damn Thing After Another: Memoirs of an Attorney General, he wrote that Trump had “shown he has neither the temperament nor persuasive powers to provide the kind of positive leadership that is needed”.

Trump, Barr said, has surrounded himself with “sycophants” and “whack jobs from outside the government, who fed him a steady diet of comforting but unsupported conspiracy theories”.

Trump responded by calling Barr “slow” and “lethargic”.

“When the Radical Left Democrats threatened to Hold him in contempt and even worse, Impeach him, he became virtually worthless to Law and Order and Election Integrity. They broke him just like a trainer breaks a horse.”

Trump had previously called Barr a “swamp creature” and a “Rino [Republican in Name Only] … afraid, weak and frankly … pathetic”.