Jubilee, Swan Theatre, Stratford-upon-Avon

A funny thing happened on the way to the birthplace...

Three surprise guests from the 21st century trespass into Jubilee, Peter Barnes's rumbustiously satirical new play about Garrick's great Stratford Jubilee of 1769. Mischievously impersonated by RSC actors, they are none other than Sir Peter Hall, Trevor Nunn CBE and Terry Hands, the first three directors of the Royal Shakespeare Company. In Greg Doran's strenuously vibrant production, this trio arrive in a dream at a point when David Garrick, the foremost actor of the age, is dithering about the financial risk of mounting his epoch-making three-day celebration of the Bard.

Knowing that the Jubilee will lead directly to the creation of the multi-million dollar Shakespeare industry, and thus to the RSC and their own careers, these anxious big-shots are there to stop Garrick from changing his mind and to safeguard their own future existence. Oh, and also to make snide remarks about each other's money, meanness and working methods. "I won't starve, on cold winter nights, thanks to my, erm, my, erm 'Memories'," simpers Trevor, "But I still need the prestige", while Terry agonises that they might have to get different jobs for which they've "no training, no experience and no aptitude".

As you'll have gathered, Jubilee is not a play that is much inhibited by reverence. In fact, just about everything, apart from the generous-spirited Garrick, comes in for Barnes's restless, broad-brushed disrespect – from the fact that not a single play of Shakespeare's was performed in all the processions, masquerades, feasts and firework displays that were laid on for London's toffs, to the philistine profiteering of the theatre-hating townsfolk who fleeced the visitors with sky-high "Jubilee prices". Above all, in a climactic even-handed duel between Garrick and the critic George Steevens, Barnes questions the justice of canonising Shakespeare, a writer who (to his mind) managed, in plays such as The Merchant of Venice and The Taming of the Shrew, to disguise moral squalor with honeyed words.

The drawbacks of making a cult of genius and of turning culture into a heritage industry is a good subject, but the largely crude pantomime humour here fails to investigate it with the penetration it deserves. It's puerility rather than bracing blasphemy that's on offer in scenes such as the one where, in a London steam room, Dr Johnson literally has a fit at the idea of the Jubilee, or where, as the rising Avon floods the festivities with sewage, a couple of Stratford yokels muse that, by comparison with them, Shakespeare "didn't know shit".

There are incidental pleasures, like the spectacle of James Boswell shamelessly using the event to promote himself and his latest book, but even potentially forceful mock-Jonsonian episodes – as when a bawdy travesty of "Cleo and Tony" by a party of prostitutes convinces a sour puritan cleric that he has experienced a Pauline conversion to Shakespeare's genius – fall flat through laboured overkill.

Nicholas Woodeson exudes the good nature and protean energy of Garrick and he performs wittily virtuosic turns like breezing through a rapid medley of Shakespeare's kings in the style of famous RSC actors. Such stunts, though, merely add to the sense that, too often here, polemical power is diffused in the atmosphere of an incestuous, end-of-term-style romp. As for seeing Stratford's mercenary tourist mentality mocked in a Stratford theatre – well, the tight-fisted burghers gave Garrick the freedom of the town: Peter Barnes may be lucky to escape with a lynching.

To 13 October (01789 403403)