Council Depot Blues, Royal Court, Liverpool

You might need to brush up your Scouseology before seeing Council Depot Blues. With their ribald repartee and bawdy jokes, the lads from the Liverpool City Council Excrement Eradication Department aren't posh talkers. But, flying high on the success of Brick up the Mersey Tunnels and Lost Soul, Dave Kirby has drawn on his own and his dad's experience working for the "Corpy" in a play riddled with Liverpool's trademark self-deprecating humour, a load of farcical moments, a stone-cold R&B score and a lorra, lorra rude jokes.

The Royal Court Theatre is fast developing a niche market for popular theatre such as this. Up the road at the Everyman, shortly to be knocked down and rebuilt in a £23m redevelopment, the famous Bistro is downstairs. At the 1938 Art Deco Royal Court, it's in the theatre itself. In a transformation of the stalls, 150 of the audience can book to sit cabaret-style at tables, enjoying a pre-show meal (including "Fruits Dee Mersey", an award-winning dish using seafood from the two rivers, with Formby asparagus) and sipping digestifs during the show. On a dull November Monday evening the tables were packed, and the theatre buzzing. In the past couple of years the theatre's chief executive Kevin Fearon has developed a niche market, finding ways of putting on plays with a largely ensemble cast, which attract a non-theatre-going audience – and bring them back.

Previously, Olivier, Donat and Fonteyn tread the boards of the Royal Court – Judi Dench made her professional stage debut here – and it has a long history as a venue for popular theatre. The audience clearly feels an affinity with what it's watching, sometimes yelling out to the actors, who react accordingly. It's popular with local playwrights Alan Bleasdale and also Willy Russell, whose Stags and Hens is the only play by either writer to feature in the Capital of Culture programme. On a short-term contract until next January (the city council agreed that it would be safe until after the high-profile Capital of Culture year), the Royal Court receives no subsidy and hasn't seen a penny of the European Capital of Culture largesse.

Somewhere in this story of a theatre that produces full-time without any funding, that auditions and rehearses in Liverpool, as well as serving 150 dinners a night, and drew 200,000 people through its doors last year, is a play waiting to be written by Dave Kirby. In the meantime, his tale of Stan, retiring from the local council depot responsible for clearing out the houses of the dead and departed, takes jokes about shovels, skips and rubbish tips to a new level. In a kind of "Carry On Liverpool" style, it sends up so-called high culture in a way that has the audience cheering to the rafters.

Gags about the militant politician Derek Hatton; Scouse-slanderer Boris Johnson ("caught in a compromising situation with a sheep"); a news report declaring "It's official, the Capital of Culture year has been shite"; a dig at the brass section of the Royal Liverpool Philharmonic brass section ("all former plumbers with the Council") and a running joke about Shakespeare keep the laughs coming in, despite being often dangerously near the knuckle.

But it is the actors inhabiting this disparate bunch of workmen who give Council Depot Blues its colour, a sense that this is entertainment at its dirty, funny best. Social misfits, these rogues are out to do as little work as possible and are desperate to escape from their dead-end job. The discovery of a genuine Gibson F5 mandolin in the house of Miss Jolly might just be the light at the end of their interminable tunnel, but all of them are after it, of course. Kirby has an X-ray eye and ear for grotesquerie, lewdness and detail that is nothing less than perfect, and, when it is pitched with such precision by a cast that includes Andrew Schofield as Danny playing blues and jazz rock guitar, with Jake Abraham as Fitzy the drummer and Roy Brandon as Jo Jo the celibate gay saxophonist, the cues for some great playing and singing are neatly woven into the story.

To 27 November (0870 787 1866)