The story of a chronically abused and illiterate young woman who refuses to let life grind her down, Precious – or Precious: Based on the Novel Push by Sapphire, to give the film its full, unwieldy title – is a starkly powerful film by gay African-American director Lee Daniels.

Claireece Precious Jones (Gabourey ‘Gabby’ Sidibe in a debut performance of rare subtlety and dignity) is an unlikely but memorable survivor: an obese 16 year old who is pregnant to her own abusive father for the second time, and the constant target of her mother’s terrifying and misplaced rage.

School offers no respite; Precious can barely read or write, and she is about to be expelled. Her only escape is a rich imagination, a fantasy life in which Precious is a diva, rich, successful, and admired and desired by all; the exact opposite of her daily life, in which everyone around her is all to quick to make it known that Precious is worthless, stupid and despised.

Just when her life seems utterly without hope, Precious is offered a lifeline in the form of literacy classes at an Alternative School where she not only learns to read and write, but to believe in herself and have hope for the future, thanks to the support of her teacher, Ms Rain (Paula Patton) and a stern but committed social worker (a de-glamourised Mariah Carey).

There have been many films about inspiring teachers and the transforming powers of hope and imagination – think Dead Poet’s Society (1989), To Sir, With Love (1967) Stand and Deliver (1988) and The Blackboard Jungle (1955) to name just a few – but none of them come close to capturing the terror and brutality of the life our titular heroine is so desperate to leave behind in Precious.

The film’s grim nature may put some people off, and certainly the cavalcade of misery Precious lives through is difficult to stomach, but while director Lee Daniel doesn’t skimp on the grim details of the story, he also imbues the film with a palpable sense of grace.

In a lesser director’s hand Precious could have been mawkish and melodramatic; instead, he has given us a study in restraint. Daniel’s light touch allows audiences to find their own route through this tale of woe, avoiding overly-telegraphed scenes and heavy-handed musical cues, and ensuring that any emotional response one has to the film is authentic rather than forced.

Equally impressive is Daniel’s work with the performers. He is clearly an actor’s director, and coaxes brilliant performances from all his cast, even Mariah Carey, whose previous track record as an actor has been poor to say the least.

But while all the cast are excellent, the two most remarkable performances in the film are those of Gabourey Sidibe as the sullen, inward-looking Precious, and comedian-turned-actor Mo’Nique, as Mary, the most terrifying and hateful mother ever portrayed on screen.

Remarkably, in the film’s gut-wrenching penultimate scene, Mo’Nique manages to make the audience sympathise with Mary, even as she reveals just how black the character’s bitter soul really is. Having already won the Golden Globe Award for Best Supporting Actress for her role in Precious, Mo’Nique is a sure-fire bet to pick up an Academy Award for the same performance.

Sidibe – an untrained actor who was studying for a degree in psychology at the time she auditioned for the film – is equally mesmerizing as Precious, whose blank gaze, anger and silence are her only protection against a brutal world.

Precious is not a comfortable ride – it will scour your soul and leave you feeling raw and exposed – but it will also renew your sense of hope and move you to tears as you watch the painful rebirth of its central character.

Precious opens nationally on February 4. Advance screenings January 29 – 31.

Stars Gabourey Sidibe, Mo’Nique, Mariah Carey, Paula Patton and Lenny Kravitz