Michael Moore, the Oscar-winning documentary filmmaker who famously grilled former US President George W. Bush's war hungry administration in his 2004 film Fahrenheit 9/11, has revealed on Twitter that he's been furiously working on a "surprise" film about Donald Trump.

It will have its premiere at a public screening in New York this evening and Los Angeles over the weekend, before being made available on iTunes, reports Deadline.

Titled Michael Moore In Trumpland, the film is based on a one-man show Moore performed in Ohio – "Trump country", as he calls it – while on the election trail earlier this month.

"You are invited to see the film Ohio Republicans tried to shut down," a press release for the film dramatically reads, referencing a back-and-forth tussle Moore recently had with the management board of a local Newark, Ohio theatre, who blocked his plans to shoot the film there, citing the filmmaker as "too controversial".

The performance was eventually rescheduled to a theatre in neighbouring Wilmington, Ohio, which agreed to host Moore over two nights on October 6 and 7 – presumably the shooting dates for the soon-to-be unveiled film.

In a recent Facebook post, Moore addressed his reasons for making the film.

"I think I know why a lot of people in Ohio and Michigan, some of them my neighbours, are voting for Donald Trump – good Midwestern people whose lives have been upended by 'the system that's been rigged against them'," Moore wrote.

"They used to be part of something that was called 'the middle class'. Now they have a chance to hit back, to pick up a virtual baseball bat and smash that old system by voting for the outsider known as Trump.

"I want to talk to these voters," he added. "I want to see if I can meet them halfway. And I want to give an hour or so of some good laughs over the craziest election year we've ever seen."

While Moore's previously proven a convincing thorn in the side to Republican politics, turning his ire to the party's stances on issues including gun control (Bowling For Columbine), foreign policy and human rights (Fahrenheit 9/11) and healthcare (Sicko), it's hard to imagine what kind of surprise smoking gun might come out of Trumpland, considering the filmmaker's views on the presidential nominee are already well known.

Earlier this year, Moore posted an article on his website highlighting "5 reasons why Trump will win", in which he apologised to readers for being "the bearer of bad news".

"I have awful, depressing news for you: Donald J. Trump is going to win in November," he wrote. "This wretched, ignorant, dangerous part-time clown and full-time sociopath is going to be our next president."

While Trumpland might not promise to be "fair and balanced", a US election campaign without a Michael Moore doco is like Christmas without panettone. We'll see what it has to offer when the first reviews filter through overnight.