‘Zero Dark Thirty” is a hit with critics and early audiences, but a bipartisan thumbs-down from Washington may dim the once-bright Oscar chances for Kathryn Bigelow’s fact-based thriller about the hunt for Osama bin Laden.

The film has come under fire for misrepresenting the role of torture in tracking down the al-Qaida leader. A few weeks ago, the battle took to the airwaves as Sen. John McCain, R-Ariz., went on radio and television to decry the Sony Pictures release.

“You believe when watching this movie that waterboarding and torture leads to information that leads then to the elimination of Osama bin Laden. That’s not the case,” McCain said on CNN’s “The Situation Room,” adding that torture had yielded false information from detainees.

The former prisoner of war explained that he was speaking out because “movies, particularly by very highly credentialed producers, directors and cast, (do) have an effect on public opinion — not only in the United States but around the world.”

The slam — and on a subject as provocative as torture — is part of a public relations nightmare in an industry where perception often trumps reality. It also underscored the slippery ground Hollywood stands on when it makes a dramatic feature based on complicated real-world events.

McCain’s remarks echoed complaints in a letter that he and Sens. Dianne Feinstein, D-Calif., and Carl Levin, D-Mich., sent to Sony on Dec. 19, the same day as the film’s limited release. The lawmakers asked Sony to correct the record; so far, the studio has not responded. Bigelow and screenwriter Mark Boal previously said that their movie “shows that no single method was necessarily responsible for solving the manhunt, nor can any single scene taken in isolation fairly capture the totality of efforts the film dramatizes.”

The senators’ criticism follows complaints by conservative watchdog groups and politicians that the filmmakers improperly gained access to intelligence sources.

“Zero Dark,” starring Jessica Chastain, has been considered an Oscar front runner after winning best picture from the New York Film Critics Circle and the National Board of Review; the film also has been nominated for several Golden Globes.

Around Hollywood, consultants working on the awards campaigns of rival films proclaimed that “Zero Dark” had suffered a hit.

“A very good piece of work now has its Oscar chances hurt,” said longtime awards consultant Murray Weissman, who is working on several films from Sony competitor Paramount Pictures. “When you get people involved at the highest level of government condemning your movie, it puts a black cloud over it.”

At the same time, some commentators are voicing support for the filmmakers and decrying what they regard as Capitol Hill grandstanding. Washington Post columnist David Ignatius accused the senators of sending an “intemperate” letter. “Why are the Senate’s most prominent members seeking to intimidate film studios and writers from discussing an issue of critical national importance?” he wrote.

“Zero Dark Thirty” is a major Oscar hope for Sony Pictures. Though the studio didn’t finance the $45 million picture — money instead came from 26-year-old Silicon Valley financier Megan Ellison — the studio is spending millions to promote the film in the hope that it can triumph at the Academy Awards over contenders such as “Lincoln” from Disney and “Argo” from Warner Bros.

“Zero Dark” follows a character named Maya, a CIA agent, on an eight-year quest to track down bin Laden — a quest that ends in the deadly raid on the al-Qaida leader’s Pakistan compound in May 2011. The first section of the film portrays torture of a detainee at a CIA “black site” that yields a critical intelligence lead.

As Sony’s major release this holiday season, the film comes with great commercial expectations. The company has unspooled an outdoor ad campaign in major cities as well as national TV spots during NFL games.

Box office has been strong since the film opened in limited release Dec. 19. In five theaters in New York and Los Angeles, the picture has grossed $1.6 million.

But a larger test of whether “Zero Dark” can weather the controversy will be its national rollout. The movie opened in 25 cities on Jan. 4 and opens everywhere else Friday, a day after Oscar nominations are announced.

Controversy over a film’s authenticity is nothing new in Hollywood. Naysayers as far back as “Lawrence of Arabia” 50 years go attacked the film for a raft of inaccuracies from the physical appearance of star Peter O’Toole to liberties taken with Middle Eastern battles and antagonists. (The film still went on to win seven Academy Awards.)

Eleven years ago, allegations arose that “A Beautiful Mind” whitewashed its subject, the troubled mathematician John Nash. Critics alleged that the movie, directed by Ron Howard and starring Russell Crowe, had overlooked many flaws of its subject. But Universal Pictures mounted a concerted campaign to tamp down the criticism, and the film went on to win the best picture Oscar.

Others have not been as lucky. In 2000, “The Hurricane,” a Denzel Washington film about the real-life imprisoned boxer Rubin “Hurricane” Carter, faced a storm of criticism about invented details and characters, particularly a racist policeman. After early buzz, the film wound up winning no Oscars.

“Zero Dark” may be in even choppier waters. Though the film is a drama, not a documentary, Bigelow and Boal have positioned their movie as based on “firsthand accounts,” as a title card states. Boal, a former reporter, told the Los Angeles Times recently that he researched the film as a journalist.

Interestingly, “Argo,” a key competitor of “Zero Dark” in the Oscar race, also centers on a CIA operative and has strong political themes. The drama about the 1979 Iran hostage crisis has taken greater liberties with history. But “Argo” has faced almost no criticism over matters of accuracy, perhaps because, though a poster declares that “the mission was real,” filmmakers and marketers have stopped short of using the word journalism in connection with the film.

Experts say that in recent years, audiences have been casting a more skeptical eye on movies based on actual events.

“Over the last 10 years, fact-based movies have been held to a much higher standard than in previous eras,” said Allan Mayer, principal partner at the entertainment publicity firm 42 West who helped manage the crisis for “A Beautiful Mind.” “It used to be when these questions were raised, filmmakers would roll their eyes and say, ‘Hey, it’s a movie.’ That fig leaf doesn’t work anymore.”

“Zero Dark” also is playing in a different arena because of its subject matter, which is both contemporary and weighty. The particulars of John Nash’s life, no matter how interesting, are not a matter of U.S. national security policy.

“This is about a government, a nation,” said one consultant who is working on rival films, “and it speaks to all of us and what we stand for.”

Los Angeles Times staff writer John Horn contributed to this report.