Simon Dillon reviews the low key but brilliant film.

Natalie Portman's superb central performance in director Pablo Larrain's low key but brilliant Jackie is certain to gain an Oscar nomination and possibly a win.

Although an obviously excellent casting decision, Portman's take on Jackie Kennedy Onassis is quite remarkable, as it demonstrates an individual who famously had to put on a front on many occasions. We are seeing someone act as though they are acting, whether to adopt the elegant poise expected of a First Lady (during a memorably awkward 1961 television tour of the White House, in which we see her being constantly encouraged to smile), or attempting to maintain composure for a Life magazine reporter (Billy Crudup), around whose December 1963 interview the film is framed. The flashbacks peels away these layers to reveal an intimate, traumatised portrait of a woman in shock, dealing with the immediate aftermath of her husband's assassination.

At the beginning of the reporter's interview with Jackie, she makes it clear that she will edit the piece, and that this will be her version of what happened, on that terrible day in Dallas the previous November. She is frank, but if she feels she is losing control, gives instructions like "Don't think for one second I'm going to let you publish that". When lighting a cigarette, she also points out that she definitely does not smoke. Yet despite this a surprisingly candid perspective emerges.

Screenwriter Noah Oppenheim's kaleidoscopic, fractured narrative accentuates the disorientated feelings of post-traumatic stress Jackie must have experienced, especially as she then has to hurriedly depart the White House, packing her things as the Johnsons move in and already make adjustments to the décor. She also has the horrible task of telling her children the appalling news, whilst planning the most elaborate State funeral since Abraham Lincoln, despite resistance from many with security concerns. Scenes such as these are intercut not only with the interview, but also of a frank discourse between her and a priest (John Hurt), with occasional flashes of the assassination itself (shown in unsparingly bloody detail). Indeed scenes where Jackie, still covered in bloodstains, returns to the White House to change out of her clothes and shower, have an intense and horrific intimacy.

Larrain makes excellent use of the slightly less wide 1:66:1 aspect ratio to visualise the profound claustrophobia of bereavement, as Jackie wanders around the White House, almost like a ghost. Bizarrely I felt reminded of horror films like The Shining in scenes like these, and in a sense this is a ghost story, with occasional glimpses of John F Kennedy (Caspar Phillipson) lurking throughout. Larrain also effectively fuses archive footage with newly shot material, which reminded me of Oliver Stone's masterpiece JFK, even though that film has a very, very different style.

Peter Sarsgaard, Richard E Grant and Greta Gerwig pop up in fine supporting roles (the latter as Nancy Tuckerman providing warm support for Jackie throughout), and Mica Levi's eerie score holds the piece together remarkably well. However, it is the subtleties of Natalie Portman's layered performance that most haunt. Jackie's famous proclamation that "There'll never be another Camelot" (a reference to the Learner/Loewe musical that her husband loved) is delivered with devastating poignancy, and lingers long after the end credits have rolled.