Hunger, Steve McQueen, 95 mins, 15 Of Time and the City, Terence Davies, 72 mins, 12A

Like buses, great British art films all come at once

This year has unexpectedly brought signs of a resurgence of that endangered-presumed-lost creature, the British art film. I'm thinking of, among others, Joanna Hogg's Unrelated, Duane Hopkins' forthcoming Better Things, and two films by established names – Hunger, by Turner Prize-winning artist Steve McQueen, and Of Time and the City, a very personal documentary by long-absent maestro Terence Davies. For all I know, these directors might balk at the suggestion that they're making "art films" – but what I mean is simply the kind of work in which distinctive film-makers pursue their vision with minimal com-promise, minimal regard for box-office prerogatives. Certainly, recent British cinema has shown us little as individual and intimate as Davies's film, or as audacious and confrontational as McQueen's.

The subject of McQueen's film is the 1981 IRA hunger strike in the Maze prison, in particular the ordeal of Bobby Sands. Hunger's imagistic style bears little relation to any other British realist political drama. Its opening section, a brilliant stroke of lateral imagination, depicts the routine of a middle-aged man (Stuart Graham), first seen washing, dressing, eating a fried breakfast, leaving his suburban semi to go to work. When we discover he's a guard in the notorious H blocks, the mundanity of his existence increases the effect of claustrophobic horror when we enter one of the cells, its walls daubed with faeces in a "dirty protest" against the British government's refusal to grant political status to Republican prisoners.

Bobby Sands (Michael Fassbender) makes his appearance 30 minutes in, hairy, raging and naked, struggling furiously against his captors: the film presents him as a Samson, soon to be bloodily shorn, or a fighting Jesus. Hunger is as brutally austere, as starkly physical a film as has ever been commercially released in Britain. In a scene of nightmare brutality, prisoners are made to run the gauntlet, and we see the marks left by real truncheons on the actors' bodies. When Sands starves, we see the effects of Fassbender's own fasting for the role: the lesions are presumably make-up, but there's no mistaking the reality of his skeletal frame. Other horrific images include the prisoners' maggoty food, and the matter-of-fact business of smearing the cell walls. Yet Hunger is at its most powerful when it doesn't seek to overwhelm. Its most insightful moments are those that spring from the more objective capacities of McQueen's artist's eye and ear, and of Sean Bobbitt's camerawork: a corridor running with urine, then swept by a cleaner's rhythmic scrape; the guard quietly smoking as snow falls, the repeated close-ups of his scuffed knuckle.

The film's first 50 minutes are so cogently compelling that what follows seems uneven. Hunger's centrepiece is a 22-minute dialogue, headed by an extraordinary 16-minute take, in which Sands and a priest (Liam Cunningham) sit at a table and discuss the ethics and usefulness of the strikers' actions. It's a remarkable sequence, yet it feels as if a one-act drama has been dropped into a film that speaks most eloquently without words. The portrayal of Sands's final days offers Bacon-like images of his tormented frame and an extraordinary shot of a bloodied sheet that fills the screen, suggestive of Christ's shroud: Hunger unequivocally applies a Passion-like iconography to Sands's death.

Yet in its final moments, the film's severity is diluted by some overtly expressive effects, personalising his experience in a way that jars with the tough detachment that precedes.

Watching Hunger for a second time, I'm not sure it's as rigorously achieved as I thought when first shaken by it. Its political background is sketchy, embodied by the instantly emotive sound of Margaret Thatcher's cyborg drone; as for making us understand the context of Sands's death, that job is left, flatly, to opening and closing captions. But, as I said, McQueen has not set out to make a conventional political film. Hunger is a work of bold artistic invention; at the very least, its must-see status is inviolable.

Seemingly more benign, but at heart just as angry, Of Time and the City is Terence Davies's portrait of his native Liverpool. It is also a self-portrait, as you'd expect from Britain's most confessional and most un-ashamedly poetic film-maker. It offers a montage of archive footage portraying Liverpool from Victorian grandeur to the present, plus elegantly photographed new material, all linked by Davies's voice-over: a stream of reminiscence, commentary and barbed wit that takes in public history, personal memoir and magnificently enraged railings against the Royal Family's post-war profligacy.

Davies's trademark of sonic collage comes into its own as he fuses radio clips, poetry and songs: a sequence mapping the advent of high-rise housing is set to Peggy Lee's "The Folks Who Live on the Hill", the ironic juxta- position proving trenchant and poignant. The director's rich speaking voice infuses the film with an intense first-person intimacy, making this a wholly "authored" film of the type rarely seen today. Terence Davies has created what is, in the very best sense, a radio essay for the screen. Radio 3 should offer him a carte blanche commission.