The Dublin International Film Festival jury doesn't give out a prize for Worst Film, but damned if Looking for Hortense didn't raise enough heckles to warrant a serious discussion about an inaugural Wooden Spoon. In the end, the jurors decided that this diabolical, nasty, cretinous thing didn't deserve the oxygen of publicity.

How on earth has this vile project crawled its way into our cinemas? It's bad enough that Pascal Bonitzer's film looks like an impression of a classically bad French movie – as though aliens picked up a random Francophone VOD channel and regurgitated their own Scary Movie version of the worst bits back at humankind.

As ever, Kristin Scott Thomas is a Kristin-Scott-Thomasy, adulterous, icy wife. As ever, there's a bourgeois husband. a teacher named Damien (Jean-Pierre Bacri) and a bourgeois broken home.

The dramedy – and the film is so atonal one hesitates to use even that compound word – is inept, but the picture's racist and homophobic undercurrents are truly eye-watering. A subplot involving a fey oriental lover makes DW Griffith's Broken Blossoms seem comparatively enlightened; a condescending narrative involving Damien and a Serbian waitress is an insult to all of Eastern Europe and to anyone in the service industry.

Badly written characters, such as Damien's overbearing, overweight father, a judge, float in and out with little explanation or consequence. Why are we watching the only French film this year that's worse than Paris, Manhattan? Just as that title attempted to profit from an association with Woody Allen, one can only think that Hortense's release is a cynical attempt to capitalise on the presence of the reliable Scott Thomas, who is currently enlivening Only God Forgives. Don't make the mistake of wandering into the wrong screen.

Get back on the Low Road, you unholy mess.