US television network CBS has declined to show adverts for the film Truth, a Cate Blanchett and Robert Redford-led political drama that details an embarrassing episode in the company’s history.

James Vanderbilt’s film centres on a 2004 report on CBS News’s 60 Minutes alleging that president George W Bush received preferential treatment during his stint in the Texas Air National Guard in the late 1960s and early 70s. At the time of the news broadcast, Bush was fighting a white-knuckle election campaign against Democratic challenger John Kerry, whose own military record was also put under the media microscope.

Dan Rather, played in the film by Redford, was forced out of his longstanding position as the anchor of 60 Minutes after rightwing bloggers suggested that memos alleging that Bush shirked his military service had been faked. CBS later apologised for the report, and producer Mary Mapes (played by Blanchett) was fired, along with three other executives.

Truth opened in US cinemas on 16 October. The studio Sony had hoped to buy advertising on 60 Minutes, The Late Show with Stephen Colbert, the CBS Evening News and CBS This Morning. But Sherri Callan, president of media buyer Callan Advertising, told the Associated Press that a multi-million-dollar offer was turned down due to what CBS has called inaccuracies and distortions in the film.

Reviewing the film after its debut at the Toronto film festival, the Guardian’s Catherine Shoard described it as a “one-note rally for the converted that gets your pulse racing even if you’re rolling your eyes”.

In one scene, a producer is seen ranting about network owner Viacom, the implication being that Viacom executives quashed the story due to their links with the Bush administration.

CBS spokesman Gil Schwartz (played by Steve Bastoni in the film) issued a statement earlier this month attacking Truth’s alleged inaccuracies. “It’s astounding how little truth there is in Truth,” he said. “There are, in fact, too many distortions, evasions and baseless conspiracy theories to enumerate them all. The film tries to turn gross errors of journalism and judgment into acts of heroism and martyrdom. That’s a disservice not just to the public but to journalists across the world who go out every day and do everything within their power, sometimes at great risk to themselves, to get the story right.”

Truth’s film-makers have responded: “Although we understand CBS wants to put this episode behind them, it’s disappointing that they seem to be so concerned about our film. The events depicted in Truth are still vigorously debated, and that’s a good thing. It’s a fascinating story at the intersection of politics, media and corporate America and features powerhouse performances from Cate Blanchett, Robert Redford and the rest of the cast. We hope people will see the film and judge for themselves.”

While Sony have not been able to advertise the film on 60 Minutes or other CBS broadcasts, publicity surrounding the network’s decision does appear conveniently well-timed for the studio, which is pushing Truth as an Oscars contender. Variety suggests that the network told Callan Advertising it would not carry ads for Truth more than two weeks before the appearance of AP’s first news story about the decision – which was on the day that the film opened in US cinemas.