The sins of a jailbird father are revisited upon an embittered son in David Mackenzie's gritty drama.

Based on screenwriter Jonathan Asser's experiences as a prison therapist, Starred Up pulls few punches in its depiction of life behind bars, delivering a flurry of beatings as characters jostle for supremacy inside crumbling walls where everyone can hear you scream.

Squeamish audiences are sentenced to their worst nightmare: a journey into an unforgiving world where disputes are settled with a slash from a makeshift shank fashioned from a toothbrush and razor blade.

Prisoner officers are just almost as cold-blooded as the offenders in their care, meting out violence to keep troublesome inmates in line. If all else fails, ringleaders are strung up from the bars of cells - their deaths falsely attributed to suicide.

Belfast's disused Crumlin Road Gaol provides a suitably claustrophobic setting and Mackenzie's cameras explore every nook and cranny, capturing a vicious assault in the showers that leaves us wincing in horror.

At the centre of madness is 19-year-old repeat offender Eric (Jack O'Connell), who swaggers into his first adult prison as if he owns the joint.

"Get your kit off - come out when you're ready," barks one of the guards, who conducts a humiliating body search.

Clothed in a regulation grey tracksuit, Eric is escorted to his cell where he expertly constructs then conceals a shank.

An altercation with prison guards leads to a spell in solitary confinement and Eric is ushered before lifer Spencer (Peter Ferdinando), who rules the roost.

"No more silliness. I want a nice quiet wing," Spencer tells Eric with an air of menace.

It transpires that Eric's father Neville (Ben Mendelsohn) is at the same facility and operates as one of Spencer's underlings. Their reunion after 14 miserable years of estrangement is far from happy.

While Eric exorcises ghosts of the past, the lad also attends anger management sessions led by a volunteer called Oliver (Rupert Friend), whose personal involvement with inmates is a source of frustration for sadistic Governor Hayes (Sam Spruell).

Punctuated by explosions of unsettling and graphic violence, Starred Up is reminiscent of Alan Clarke's seminal 1979 film Scum, which chronicled one young man's journey through the hell of a British borstal.

Mackenzie's film is almost as suffocating, anchored by a no-holds-barred performance from O'Connell that's a far cry from his formative years on ground-breaking Channel 4 teen drama Skins.

The 23-year-old Derbyshire actor electrifies every frame, offering glimpses of fear behind Eric's cocksure facade as he rages against an imperfect system.

Friend and Mendelsohn are compelling in support and Asser's script steadfastly refuses to polish any rough edges with pat sentimentality.

For these characters, the milk of human kindness is always sour and they have no choice but to swig and swallow.