For a decade he was Donald Trump's "fixer," the man who said he would "take a bullet" for his boss.

But when Michael Cohen raised his right hand in front of a Congressional committee he threatened to do his best to torpedo the Trump presidency.

He laid out a litany of accusations including that Mr Trump had only run for office for publicity, that he knew in advance about Wikileaks releasing Russian-hacked emails, that he committed criminal acts in the White House, and that he was a "racist" who called black people "stupid."

Cohen hoped it would be a "John Dean moment," recalling how Richard Nixon's White House counsel turned on him. After watching the testimony Mr Dean himself said: "His mea culpa was excellent. I find him a good witness. This is a witness who can cause the president trouble.