There’s nothing quite so naff and depressing as a British comedy misfire, and Me, Myself and Di is the real deal: a miserably unfunny romcom about Bolton’s answer to Bridget Jones. Her name is Janet Brown (Katy Clayton), and she is a chirpy 30-year-old virgin who works in a supermarket stacking shelves. Janet is devastated when an internet date stands her up: “He took one look at me and ran off because I’m fat and ugly,” she sobs. “You’re not ugly,” quips her glam best friend Diana (Lucy Pinder), always ready to knock Janet’s self-confidence. The world lays indignities upon Janet and then film throws on some more. The character is so thinly written that there’s little for Clayton to do other than perform her with a kind of mouth-open gormlessness.

Most of the film is set at an annoyingly anachronistic holiday camp in Rhyl where the two friends go on holiday for a week. Diana gives Janet a makeover for the trip; transforming her into Jeanette De Brun (“It’s French, dead classy,” she reasons). The comedy here is meant to be affectionate social satire, I think. But it feels snidey: a mickey-take of working-class characters hilariously mispronouncing “Tenerife” and “Les Misérables”.

Saying that, it’s pretty crass about the upper crust, too. You know as soon as inefficient toff John (Tyger Drew-Honey) stammers a “hello” that he’s Janet’s love interest. He’s on holiday with his cartoonishly snobbish mother (Jenny Funnell) and sister. The silly, kids’-TV-ish plotline here is that Janet maintains the fiction to John that she is wealthy, well-spoken Jeanette from “higher Bolton”. He sees through the act, of course, and loves her for who she really is.

The whole thing is pretty hopeless but I did laugh at one gag, when Janet uses the loo in John’s static caravan. His mum calls after her: “No solids, mind deary.”

• Me, Myself and Di is released on 11 June in cinemas.