US President Donald Trump's niece offers a scathing portrayal of her uncle in a new book, Too Much and Never Enough, How My Family Created The World's Most Dangerous Man, blaming a toxic family for raising a narcissistic, damaged man who poses an immediate danger to the public, according to a copy obtained by The Associated Press.

Mary L Trump, a psychologist, writes that Trump’s re-election would be catastrophic and that “lying, playing to the lowest common denominator, cheating, and sowing division are all he knows”.

In her book, Mary Trump, who is estranged from her uncle, makes several revelations, including alleging that Trump paid a friend to take the SATs in his place.