Donald Trump has called the former FBI director James Comey a “weak and untruthful slime ball” after his new book made a string of damning claims about the president.

Mr Trump said Mr Comey, who he fired last May, should be prosecuted for leaking while in office as other White House figures questioned the ex-intelligence official’s integrity.

The furious response followed a string of details from Mr Comey’s new book, A Higher Loyalty, emerging ahead of its publication on Tuesday.

In the book, a copy of which The Telegraph has obtained, Mr Trump is depicted as an “unethical” bully who is “untethered to truth” and has little regard for the institutions of US democracy.

TRUMP COMPARED TO MOBSTER

Mr Comey compares the president to a mob boss, writing: "The silent circle of assent. The boss in complete control. The loyalty oaths. The us-versus-them worldview.”

“The lying about all things, large and small, in service to some code of loyalty that put the organisation above morality and above the truth."