Documentary film-maker Michael Moore has said he knows “for a fact” that Donald Trump does not want to be president of the United States and claims the Republican nominee is now sabotaging his own campaign in order to avoid the Oval Office.

Moore, writing on The Huffington Post, says that Trump ran for president as a negotiating tactic, hoping to leverage a higher pay packet from NBC. The broadcaster had formerly employed Trump as the star of the reality TV show The Apprentice, but fired him after he called Mexican immigrants “drug dealers” and “rapists” at his campaign launch.

According to Moore, who does not name his source, Trump continued his campaign only to increase his stock with other television networks.

“And then something happened,” Moore writes. “And to be honest, if it happened to you, you might have reacted the same way. Trump, to his own surprise, ignited the country, especially among people who were the opposite of billionaires.”

Moore says Trump found the attention his campaign attracted intoxicating.

“Trump fell in love with himself all over again, and he soon forgot his mission to get a good deal for a TV show,” Moore writes. “He was no longer king of the deal-makers — he was King of the World!”

Moore then catalogues a series of incidents from the past few weeks that have seen Trump’s approval ratings plummet. Citing the nominee’s attacks on the family of Humayun Khan, a Muslim American who was killed while serving in Iraq, and his implication that “second amendment people” could use gun violence against Hillary Clinton, Moore suggests that Trump’s outlandish behaviour was an attempt to “self-sacrifice” his campaign.

“Maybe the meltdown of the past three weeks was no accident,” writes Moore. “Maybe it’s all part of his new strategy to get the hell out of a race he never intended to see through to its end anyway.”

Moore finally suggests that Trump would give up the Republican nomination rather than lose on election night.

“Trust me, I’ve met the guy. Spent an afternoon with him,” he writes. “He would rather invite the Clintons AND the Obamas to his next wedding than have that scarlet letter (“L”) branded on his forehead seconds after the last polls have closed on that night.”