At what point did cliché and stereotypes become a dramatic convention? The 1960s were not so long ago as to excuse the assumption that there were only two types of English people – cheeky (i.e. rude) cockneys and toffs, so the fact that the 1960s of We’ll Take Manhattan seems to only be inhabited by these charmless broad brushstrokes must be a deliberate stylistic choice by writer and director John McKay. It’s hateful.

You don’t need to have seen We’ll Take Manhattan to know what’s coming at every juncture. As if directing some tedious Restoration comedy, the imagined events which took place prior to and during photographer David Bailey and model Jean Shrimpton’s relationship are enacted as if to a checklist of required scenes.

David’s roguish (i.e. offensive) nature, Jean’s naiveté and the fashion world’s fustiness are all demonstrated with the subtlety of a slow wink to camera.

Bailey, played by newcomer Aneurin Barnard, is more Frankie Cocozza than David Hemmings (who played the first fictional portrayal of the legendary snapper and swordsman, in the 1966 film Blow Up). We see him rogering a member of minor royalty before quitting his job in the manner only people in bad plays do: “I’m orf to seek me fortune so I am” (he doesn’t say this but it’s not far off).

Shrimpton, played by Karen Gillan, is a nervous mouse with pushy yet provincial parents – taught to model by balancing a book on her head.

To cut a long story short, Cocozza and mousey Pond team up, they both get very famous despite the fashion world’s doubts, shocking everyone by taking photos with her knees showing, have some sex, and have some of those stilted rows only people in dramas like these have: “I’m the cheap tart who’s having an affair with a married man” (she does say this, unfortunately).

We’ll Take Manhattan is like an insultingly dumb children’s programme with shagging in it. And the worst part is that you just know there’s a commissioning editor somewhere who thinks this is fine, that this is a perfectly valid way to tell the story of two people who are still alive and whose lives must've been so much more complicated, interesting, and nuanced than the one-dimensional pantomime presented here. This from the channel that gave us Dennis Potter, Stephen Poliakoff, Alan Bennett… it’s just not good enough.

We can’t criticize the acting because they have so little to work with. We know Karen Gillan is an effective actor; she’s made us cry often enough as The Girl Who Waited. But the supposed emotional climax – Shrimpton in the bath as Bailey drowns his negatives and declares his love for the first time – plays like the first run through of a script they’ve not seen before. You’ll find it near impossible to care.

We’ll Take Manhattan can be seen on BBC4 at 9pm, Thursday, January 26.