Pig Farm, St James Theatre

How wonderful it would be if Greg Kotis's play was a rapid response to David Cameron's alleged interest in porcine affairs. Not only wonderful to those still laughing about the imaginary high jinks at Oxford 20-odd years ago (the story will never not be funny), but a whole lot more dramatic and amusing than Pig Farm is in reality.

“Pig Farm,” according to the programme notes, “is an hilarious tale of regular folk, human sludgery and the American dream dragged through the mud.” Note the farm-based puns, the loose use of the word hilarious, the high-concept concept. What it is, though, is a mess.

We're in present-day America, at Tom and Tina's filthy kitchen (great design by Carla Goodman), on the farm where they raise 15,000 pigs. Tim (Erik Odom), their nice but dim farmhand, is tasked with counting the critters under a threatening sky - “it'll turn the farm into mud” - while along comes the very precise Teddy (Stephen Tompkinson) from the Environmental Protection Agency to check everything is in order. The more alert among you will have noticed that all the characters, including those offstage, have names beginning with “T”, which leads to some totally tiresome alliteration. See, I can do it too.

Tina (Charlotte Parry, pictured right) wants a baby, but Tom (Dan Fredenburgh) is strangely reluctant to do the necessary deed – a deficiency that young Tim, on release from a juvenile detention centre, is only too willing to put right. In doing so, he “becomes a man”, a phrase that, like many in the script, including “faecal sludge”, is deliberately silly, melodramatic (heightened by the theatrically Southern accents) and endlessly repeated.

Tom doesn't notice what's going on under his nose but is suspicious of Teddy, and he's right to be, as he has been dumping pig slurry in the nearby river and the government inspector is on the hunt for the culprit. As everybody eventually works out everybody else's dirty deeds, the play turns into farce and everyone and everything gets covered in mud, weapons are drawn and foul play with the pigs is uncovered (not the Oxford undergraduate sort).

Kotis wrote Pig Farm in 2006, but still it's difficult to believe that he also wrote the audaciously odd musical Urinetown (which was in the West End last year); if he was aiming at pastiche of the “death of the American Dream” plays so central to the modern US canon, he has fallen some way short. Maybe he slipped in the faecal sludge. The cast, directed by Katharine Farmer, play this hokum with utter conviction. Credit to them.

• Pig Farm at St James Theatre until 21 November