Just in time for the migration of children from their summer stations in front of phones, games consoles and laptops back to full-time education comes this Swiss-set tale of a mother on the edge. An outstanding Ophélia Kolb (arguably best known to anglophone audiences for playing the accountant Colette in Call My Agent!) stars here as Jule, a single woman trying to hold it together for her brood of three. Eldest child Claire (Jasmine Kalisz Saurer) is just entering puberty and is savvy enough to work out that mama isn’t always strictly truthful about why she wears an ankle monitor that beeps when she strays from certain areas. (Jule’s explanation that she has weak bones doesn’t really cut it.) But younger brothers Loic (Paul Besnier) and Sami (Arthur Devaux) just read it as normal that Jule disappears for long periods of time, leaving them abandoned at a cafe, for instance, mostly worried that she might not be back before it gets dark.

Director Jasmin Gordon, working off a script she co-wrote with Julien Bouissoux, is mining a seam similar to the one the Dardenne brothers have worked for years: a dirty, morally ambiguous realism that’s mostly on the side of the poor and disenfranchised. That said, it’s often a challenge to sympathise with stroppy, self-deluded Jule, who gets into a fight with a housing services representative who’s only trying to help her – particularly after he dares to say that Loic’s Asperger syndrome is basically the same thing as autism, a definition Jule refuses to accept. At one point, she breaks into a house she wants to rent to show the kids where they’re supposedly going to live next, when realistically that just isn’t going to happen.

Obviously, Jule is no mother of the year, but Kolb gets across her depth of feeling for the kids even if that love is sometimes spiked with selfishness. Despite the bleak signs of poverty amid all the Swiss bourgeois propriety, there are also moments of humour, like when Jules fakes up a mess in the kitchen to make it look like she baked a store-bought cake herself from scratch. The scene of her and the kids dancing to Build Me Up Buttercup by the Foundations as tears run down her face would draw sobs of sympathy from the hardest Alpine granite. Overall, the film is a touch trite at times, but Gordon coaxes touchingly on-point performances from both the kids and Kolb.

The Courageous is in UK and Irish cinemas from 5 September.