We assemble in the courtyard of the George Inn for this promenade version of literature's most famous pilgrimage. But matters begin ominously with the Cook being sick, the Miller urinating over a balcony and the Prioress announcing: "Je suis tres perplexed." The air is filled with a fake jollity that suggests we are in for an evening of Carry on Chaucer.
And so it proves in Gareth Machin's production, which offers us five tales in different Southwark locations. It starts in St George's Gardens with The Knight's Tale. But Chaucer's delicate blend of courtly romance and commonsensical irony, as Palamon and Arcite fall for the same girl, gets swamped under a bovine heartiness. I'm not sure whether the lowest point is reached when Theseus's kingly companion asks one of the audience to take a snap ("One for the album") or when the followers of Venus and Mars engage in mock-rock routines.
We move on to Little Dorrit Court for the Miller's and Nun's Priest's Tales. Everyone remembers the rude bits from the former, where naked bums are first kissed and then branded; but the joke here is undermined by visibly prosthetic posteriors protruding from a curtain. Matters marginally improve with the Nun's Priest's cock-and-hen story thanks to the presence of Michael Roberts as a predatory fox exuding a camp suavity. But we lose sight of the comic realism of Chaucer's fable where male arrogance is pitted against female practicality.
Finally we progress to Borough Market and the millennium courtyard of Southwark Cathedral for the tales of the Pardoner and the Wife of Bath. But by now my patience was exhausted. This adaptation, by Machin himself and Ian Hastings, gives us little sense of the close relation of tale to teller, or of what Chesterton called Chaucer's "balanced and delicate habit of mind". With one or two exceptions, the evening also offers an orgy of coarse acting.
There is something about the English summer that seems to encourage deadly theatre: we sit, or stand, under lowering skies in conditions of mild discomfort watching galumphing versions of revered classics. But here, as we journeyed through Southwark, passing people sitting happily in bars and cafes, I could only look on in curdled envy.
· Until July 10. Box office: 0870 0600 100.