There’s a Sinatra song that goes, “Saturday night is the loneliest night of the week” – a lover’s lament that might just as well apply to the gaggle (or is it giggle) of stand-up comedians depicted in Roy Smiles’ play who are waiting back-stage to go on and slay the weekend punters in a scuzzie South London comedy club.

Apart from shooting down the occasional heckler, out there in front of the mike it’s all patter and punch-lines, while in the grim dressing room with a soil pipe running down the back wall, the fake show biz egos, phoney relationships and flaky career moves turn this particular Saturday night into the un-funniest night of the century.

According to Smiles, the world of professional comics is about as amusing as the Ho-Ho Club’s blocked toilets, and he’s already made a success from knocking down stand-ups with this play’s previous incarnation, Stand-Up, directed by Roy Marsden and performed at the 1999 Edinburgh Fringe and at London’s Old Red Lion. But his re-titled, re-flushed, and altogether less toilet-trained version has the additional advantage of a new cast, director (Karl Howman) and designer (Neil Pollard) who tie all the comic threads together to evoke a kind of cynical show business battle zone where the smell of the greasepaint has long given way to a behind-the-scenes pong of stale urine and fear.

Sally Lindsay, last seen pulling pints and getting pregnant as Rover’s Return landlady Shelley Unwin in Coronation Street, is on form as buxom top banana Linda Walsh, an ex-Tesco check-out girl from Bolton (home of Peter Kay’s Phoenix Nights) who has become a Channel 4 star by delivering a ballsy act that would make even Bernard Manning blush. While she cracks-up the crowd with her below-the-thong dildo gags and cops off between sets with ambitious camp comic Tony Watts (Stephen Dean), her morose husband-cum-dogsbody Stan (Billy Miller) is reduced to whining about his miserable life at home and complaining that comedy only matters to those who do it “while the rest of us live in the real world”.

Meanwhile, Smiles himself plays moonfaced Mal Springer whose once promising career as a funny man is on the slide but is still clinging to the forlorn hope that humour can “make tyrants quake”, and as nervous novice Debbie Thomas, Katy-Jo Howman gives a brilliantly observed portrait of a new girl petrified by stage fright as the spotlight closes in on her terrified but pretty face before her debut gig ends in stunned silence.

True, this is one stand-out moment of extreme dramatic honesty in a play that sometimes seems unsure whether it’s going for wisecracks or tackling big subjects. But if it’s laughter you are after, look no further than Roger Kitter playing tight-wad Dave Harper, the Ho-Ho Club’s cigar-chomping owner and resident compere. “The death scene from Bambi got more laughs than you did,” Harper snaps at the jittery Debbie; and Kitter delivers laugh lines like this with the perfect timing of an old skool master comedian. All aspiring stand-ups should be required to see him in action – any night of the week.

- Roger Foss