“The premise is hilarious,” says Jonathan Gershfield of his feature debut. Maybe so - to the director of MTV’s tact-bypass Strutter.

But not to the tube workers who staged an angry protest at the film’s premiere. Nor presumably to the families of those struck by trains on a weekly basis, accidentally or otherwise.

Lumbered with such an unreliable timetable, it’s unsurprising that Gershfield doesn’t know where to stop or for how long, trying every station from Gallows Humour to Tear-Streaked Sentiment, calling at Slapstick, Farce and Tragedy.

Passengers for Original Comedy are advised to seek an alternative route.

Probably not the safest vehicle for Mackenzie ‘Gareth from The Office’ Crook to choose for his first crack at a movie lead, then.

Still, he gives it his worried-looking best as Paul Callow, a bookish Underground driver who dreams of escaping London to write novels at a remote Scottish hideaway.

After watching helplessly as his train notches up two fatalities in one week, Paul’s colleagues enlighten him on the ‘three and out’ rule: one more victim before the month’s out and he’ll be retired out on ten years’ salary.

With assisted suicide in mind, Paul gets his wires crossed with a cannibalistic French weirdo (Anthony Sher) before stopping Meaney’s abrasive Dubliner from throwing himself off a road bridge.

The pair make a deal. Paul gives Tommy £1500 to blow over the weekend; Tommy becomes Paul’s third victim first thing on Monday.

But since Paul wants to keep an eye on his investment, he’s forced to tag along as Tommy heads north to make peace with Rosie and Frankie (Staunton and Arterton), the wife and daughter he hasn’t seen in eight years.

First stop Liverpool for a spot of burglary to steal back a trinket Tommy lost to an old workmate (Gary Lewis). And a cameo appearance by Kerry Katona as, ahem, a Scouse slapper.

Then it’s on to the Lake District where Paul receives a warmer welcome from Frankie than her old man, and the film goes into blarney overdrive as we all suffer for Tommy’s sins when Rosie bursts into song.

Crook puts in solid work and the roguish Meaney can be forgiven for most things. But they’re both undone by characterisation which is as muddy as the tone.

Paul aspires to be a writer but hasn’t written anything, while Tommy’s back-story is explained away by a shark metaphor: “If I stop swimming, I’ll die.”

It would be easier to overlook the dubious premise if it wasn’t so morose. Seize the day? You’ll be more inclined to seize a blanket and draw the curtains.

One thing you can always rely on with ropey British comedies, though: there’ll be another one along in a minute.

Elliott Noble