Tony Schwartz, the co-author on Donald Trump's infamous 1987 book The Art of the Deal, has said he believes Trump will soon resign from his position as POTUS.
The ghostwriter, who spent 18 months working on the book with the business tycoon in the 1980s, has been one of Trump's most vocal critics since he started running in the presidential race.
On Thursday, Schwartz tweeted: "The circle is closing at blinding speed. Trump is going to resign and declare victory before Mueller and congress leave him no choice."
The comments refer to the criminal investigation into Trump's involvement with Russia during the election campaign last year. Former director of the FBI Robert Mueller III is at the helm of the investigation.
"Trump's presidency is effectively over," Schwartz wrote in a second tweet. "Would be amazed if he survives till the end of the year. More likely resigns by fall, if not sooner."
However, he advises that people continue to keep the pressure on the President: "Trump must be isolated. Resistance every day. The end is near but must keep pressure high."
"Almost all of Trump's limited attention is focused on beating down his critics. No time for governing which doesn't interest him anyway," he tweeted earlier today.
In November, after Trump's victory at the polls, Schwartz wrote that he will continue to give away any royalties that he earns from The Art of the Deal. He has said that feels responsible for helping Trump rise to fame in the 1980s.
In an interview with CNN last year Schwartz said he was serving as a voluntary campaign adviser for Hillary Clinton as "penance" for having created "a man who has become a monster".