Jefferson Steel, a huge (in Mitchell Mullen literally!) though faded celebrity of action-movie fame, in a career move designed to revive his ratings, finds himself booked to play King Lear, not at the RSC but in the village hall at Stratford St John, Suffolk – thanks to his agent's hazy grasp of UK geography.

Jackie Morrison & Mitchell Mullen
Jackie Morrison & Mitchell Mullen
© Philip Tull

The local amdram group's members are hugging themselves for securing Steel's services to save their village hall and welcome him with the obsequiousness due if he really were "every inch a king." Until the spoilt celeb starts fulminating in language so colourful, it comes with a warning!

Can feisty director Dorothy (doubling as the Fool and Cordelia!) soothe everyone's ruffled feathers? Will nasty Nigel, leading man manqué, sulking at giving his Kent not his King, stop upstaging the star?

Will starry-eyed Mary (doubling Goneril and Regan – and hosting Steel in her B & B) idolise her guest no matter what? Will Denis (Gloucester and set builder extraordinaire) find the right ingenious solution to how to put out his own eyes? And what might glamorous Lauren, wife of the ale baron sponsoring the show, and sassy Jessica, Steele's own latch-key daughter, bring to the production?

This terrific comedy packed with killer comic dialogue has a great story, with plenty of twists and turns. The characters may be recognisable, but that's part of their charm, and the cast have as much fun as the audience (who roar with laughter throughout), relishing those characters and their lines.

The Hislop/Newman partnership is responsible for scripts for iconic shows including Spitting Image and Dawn French's Murder Most Horrid and these pedigree chums of the comedy world show their class in brilliant comic riffs with a joke in every line topped only by the next one, all delivered with perfect precision by this fine cast.

They are also masters of the running joke. Steel's mounting infuriation as Mary gushes over his acting, while actually mistaking him for a series of other action-movie stars from Bruce Willis to Harrison Ford, gets funnier as he becomes more apoplectic.

And trust these two fine writers to send up every trend in our modern onscreen, online life, from trending on Twitter to rehearsing via Skype. And how's this for an insult as Steele spits out his sponsor's beer on camera? – "I've tasted better spinal fluid!"   

Many of the cast and creatives are regulars at the Watermill, and it's clear they bring plenty to the party to which they are returning. Director Caroline Leslie cleverly exploits the very believable charisma of Mullen's grizzly bear of a Steel, so that the locals revolve around him, all reacting differently to his scatological malice and paranoia.

Jackie Morrison's gently assertive and ascerbic Dorothy has the measure of him and Sarah Moyle's Mary and Damian Myerscough's Denis are equal delights in their different ways of proving their devotion to him. Michael Hadley's Nigel is a deliciously malicious actor laddie scorned.

Emily Bowker's Lauren catches the upbeat smiley quality of the PR, albeit an ad hoc one, for her husband's ale empire; and Eleanor Brown's Jessica changes the dynamic at just the right moment, a pleasingly mouthy neglected daughter.  

The Watermill's intimate space is a perfect shoe-in for the Village Hall. Designer Tom Rogers rises magnificently to the challenge of fitting multiple sets into the space, from a William Morris wallpapered B & B parlour to the hall's rouched curtains reminiscent of old cinemas – all perfectly lit with changing colours by Tim Lutkin.

Rogers uses a series of walls pushed across the "hall" to composer Paul Herbert's gorgeous atmospheric music and songs with lyrics by Shakespeare and his near contemporaries, attractively sung by different cast members. So the scene changes are part of the action, especially as effected by members of the community ensemble, actually recruited to play roles including the backstage staff! The evening is a total and mounting delight.

A Bunch of Amateurs runs at the Watermill Theatre, Newbury until 28 June.