Razor Films, makers of 90-minute documentary "Being Chlöe", expected the next election result to be the logical conclusion to the movie's story arc.
The proposal framed the film as an observational documentary chronicling the highs and lows of being an "openly gay, polarising, but immensely popular, millennial politician".
It was not intended to be a "hagiography" or portrayal of Swarbrick as some sort of saint, the NZ On Air documents added.
The documentary aspired to capture a broad audience beyond millennials, women and LGBTQI+ communities.
The proposal also quoted National Party MP Judith Collins' admiration for Swarbrick as an example of the Green MP's appeal across political lines.
NZ On Air staff discussed risks, saying funding support could be perceived as an endorsement of the politician.
But NZ On Air said Razor Films had success with previous documentaries about Swarbrick.
The agency also said Swarbrick had attracted significant national and international interest.
NZ On Air was a minority funder in the project, so the film's viability relied on other funding partners coming forward.
Act Party leader David Seymour this week said Swarbrick should reject any role in the publicly-funded documentary.
He said NZ On Air was supposed to be politically neutral but now seemed anything but.
"It's bad for New Zealand. It's bad for our democracy."
Media commentator Bill Ralston said the NZ On Air funding decision appeared to be problematic, even tone-deaf.
Ralston said it could be argued if the agency wanted to fund a documentary about a Green Party MP, it should do the same for all other parties in Parliament.
Former arts, culture and heritage minister Chris Finlayson told Newstalk ZB the documentary was a misuse of taxpayer money.
But political studies expert Professor Bronwyn Hayward said despite the backlash, there was value in viewers learning more about MPs through documentaries.
Producer Letisha Tate-Dunning earlier this week said the new project was a documentary following Swarbrick's personal journey and daily life as an MP over the next two years.
"Neither NZ On Air, the Green Party, or Chlöe herself have editorial control of the film. Chlöe does not benefit financially from the film," Tate-Dunning said.