Donald Trump's administration is in damage-control mode after senior aides and appointees privately said he was “unhinged”, an “idiot” and had the intellectual capacity of a “fifth-grader”, according to an explosive new book.

The US president’s senior aides are also quoted expressing fears he could come across as a “goddamn dumbbell” and has gone “off the rails"

The claims provoked an angry response from the president, who took to Twitter on Wednesday to call for tighter libel laws.

"Isn’t it a shame that someone can write an article or book, totally make up stories and form a picture of a person that is literally the exact opposite of the fact, and get away with it without retribution or cost," he wrote. "Don’t know why Washington politicians don’t change libel laws?"

However, insiders said he was rocked by a portrait of a White House in chaos. His top economic adviser reportedly even “stole” letters from his desk to stop the president making dramatic changes in America’s trade policy.