It’s a hard-knock life for six godforsaken denizens of London in the gritty directorial debut of Ben Drew aka Plan B.

Purportedly based on real people and real events, Ill Manors pulls no punches in its depiction of the lengths to which some people will go to survive on the streets of the capital. It’s a visually arresting descent into the darkest recesses of human suffering, cutting together different film stocks to create a nightmarish vision of a city under constant surveillance from CCTV cameras, mobile phones and nosey neighbours.

Drew introduces his protagonists in the best way he knows how: with a potty-mouthed rap and some similarly gritty imagery.

A cute injection of pace keeps the first hour zipping along at a fair lick before the sinewy plot strands become entangled and the screen glisters with anguish and despair.

Drug dealer Ed (Ed Skrein) is caught in a police sting and he quickly offloads incriminating evidence to associate Aaron (Riz Ahmed). Flashbacks to their formative years at St Erica’s children’s home for boys affirm their fraternal bond. While Aaron waits for Ed’s release from custody, he crosses paths with illegal immigrant Katya (Natalie Press), who has been sold into sex trafficking and must make a stark decision about the future of her newborn child.

Torn between his head and his heart, Aaron faces an agonising choice of his own that has dramatic repercussions for the scheming landlord of the Earl of Essex pub and his wife Carol (Jo Hartley).

Aaron also encounters junkie Michelle (Anouska Mond), who stumbles down a sickening and destructive path in search of her next hit.

Elsewhere, schoolboy Jake (Ryan De La Cruz) attempts to blag some gear from gang leader Marcel (Nick Sagar), but acceptance comes at a price. “Go over there and smash him in. Then you’ll get your stuff!” orders Marcel, pointing to Jake’s timid classmate.

Former dealer Kirby (Keith Coggins) tries to reassimilate into a world that dragged him down 15 years ago. Meanwhile, volatile dealer Chris (Lee Allen) loses his cool when his sister is caught in the crossfire of a revenge shooting and two sassy teenagers, with dreams of a modelling contract, are in the wrong place at the wrong time.

Ill Manors is an assured debut that uses a robust script as a solid foundation for flashes of directorial brio.The fractured chronology allows Drew to hold back dramatic resolutions to the myriad conflicts until the very last second, intimating hope where there turns out to be none whatsoever.

The ensemble cast reward the writer-director with compelling portrayals of tortured souls who have almost given up hope of escaping the misery. In most cases, their pessimism is well placed.

‘This is the story of me, Jack,” explains the socially awkward narrator (Simon Pegg) of A Fantastic Fear of Everything, a children’s author whose attempts to branch out into crime thrillers have left him with a paralysing fear of almost everyone. Thus, he becomes a recluse in his dirty flat, occasionally telephoning his shrink Dr Friedkin (Paul Freeman) for comfort.

Out of the blue, Jack’s agent Clair (Clare Higgins) invites him to lunch. She pleads with him to churn out another story about his beloved character, Harold The Hedgehog. Unperturbed, Clair insists that he takes a meeting with head of scripts, Harvey Humphreys (Kerry Shale), that evening. So Jack steels himself for a trip to the Lotus Laundrette, where he crosses paths with beautiful stranger Sangeet (Amara Karan), community support officer Taser (Henry Lloyd-Hughes) and a serial killer .

The film is is a fascinating, yet flawed, experiment that fails to engage us on an emotional level. Jack provides narration throughout, which veers from the mildly comical to the dull, while Pegg performs Mr Bean-style slapstick with superglue, a pair of soiled underpants and a smoking oven.

The inconsistent tone proves unsettling, though not in a way to benefit the film.

Best known as the frontman of rock band Kula Shaker, director Crispian Mills strives to impose himself on his creation but like Dr Frankenstein, he is not in charge of this monster.