“I, Daniel Blake” tells the story of an honest man trying to do the right thing who is thwarted by idiocy, arrogance and a byzantine bureaucracy at every turn.

It’s as frustrating as it is relatable. And probably necessary. Ken Loach came out of a short retirement to make the film, and, working with screenwriter Paul Laverty, he lacerates the British benefits system, a mess that serves as a stand-in for any heartless bureaucracy that will be recognizable to anyone who, like the title character, waits 48 minutes on hold for crucial assistance that almost certainly won’t be forthcoming.

Subtle, it’s not, but it is effective.

Daniel (comic Dave Johns) is a 59-year-old carpenter who has had a heart attack, which caused him to fall from scaffolding. We meet him (or hear him, actually, over the opening credits) answering a series of absurd questions relating to his health and his ability to go back to work. His doctors say he is not at all ready. A clerk disagrees, so the proud Daniel is denied benefits. He can appeal, which sounds easy enough in theory.

But not at all in practice. The first time he visits the benefits office in person, Daniel gets kicked out before he can even get started. That’s because he comes to the aid of Katie (Haley Squires), a single mother of two kicked out of her flat who has committed the unforgivable sin of being a few minutes late, having gotten on the wrong bus.

Daniel befriends Katie and her children, showing them tricks to warm their unheated apartment, carving toys for the kids and taking care of a lot of little tasks. He senses their need — a scene in which Katie’s daughter comes into her mother’s bed at night, crying that school kids made fun of her because her shoes were falling apart is heartbreaking — but, a widower and loner, he clearly enjoys their company.

It beats everything else going on in his life. He must work at least 35 hours a week looking for a job, even though if anyone was hiring (they aren’t), he couldn’t take the offer, on his doctors’ orders. It’s a miserable, Kafka-esque cycle, overseen by heartless bureaucrats. It’s especially tough for Daniel because he has never used a computer, and everything is online. When one woman in an employment-assistance office spends too much time helping him, she’s upbraided by her supervisor.

If it sounds bleak, that’s because it is. There are a few lighter scenes with Daniel’s neighbor, China (Kema Sikazwe), who is trying to get a business selling bootleg sneakers off the ground. But for the most part it’s one bad break after another, a trail of frustration that Daniel longs to leave but can’t. It’s humiliating, he tells one government drone, who regards the entire conversation as an annoyance.

As with any Loach film, there are no Hollywood conventions here, just a realism that drives the story. He won’t let up, and at times the vibe is almost suffocating. But Johns makes it all bearable. Inviting, even. His performance has such a gentle humanity, even (especially) in the darkest scenes that you can’t turn away. You don’t just root against the system. You root for him, and that’s an important distinction.

Bill Goodykoontz, USA TODAY Network

★★★

Sundance Selects presents a film directed by Ken Loach and written by Paul Laverty. Rated R (for language). Running time: 100 minutes. Available on demand and opening Friday at the Music Box.