A large yellow poster outside Worthing Pier's Pavilion Theatre proclaims Monday evening's attraction in 4ft letters: Star Search '94. But this a talent show with a difference: three hours of unmitigated mediocrity drowned in a sea of abuse. Performers - amateur and professional - are subjected to screaming insults, stamping and booing, and a bombardment of missiles including fruit, sweets and inflatable toys. Some spectators lean against the stage reading newspapers, others hold up banners displaying expletives to signal their disapproval.

Inside the auditorium, this evening's crowd is already fractious. People chant and stamp their feet, eager for the first victim. Doc Cox (erstwhile presenter on That's Life), dressed in a glitzy sequinned jacket, coaxes the audience along.

'Let's have a big hand for Terri Wylie - the singing grandmother from Milton Keynes] She has appeared on Anglia Live and is a karaoke champion.' Ms Wylie, 44, pony-trots around the stage in a white fringed miniskirt, cowboy hat and boots, delivering 'Jambalaya' with a dubious Louisiana twang. By the second chorus, she is dodging assorted inflatables, paper balls soaked in beer and a shower of confectionery. The audience's antagonism intensifies but she just smiles and sings louder. One group begins to chant 'Off, off, off' and the whole auditorium follows suit. A pensioner sitting behind me takes off her shoe and bangs it on a steel tray.

Ostensibly the singers, dancers, poets and celebrity impersonators put up with this in the hope of winning the Star Search title. In reality, they are selected as fodder for an unrelenting crowd whose collective heckling abilities thrive on an appalling lack of talent. 'If I just put on the good acts, 50 per cent of the audience would stay away,' says Trevor Gray, the theatre's business development manager.

Mr Gray, 43, with a blond Barry Manilow-style hair-do, has organised the contest since 1982. Then it was full of 'old ladies sitting in rows and applauding politely'. The behaviour has changed radically in the past two years, accompanied by a rapid turnover in comperes. 'We've got through seven now,' Mr Gray says. 'One disappeared - we think he had a nervous breakdown.' Judging by the freedom of expression the crowd enjoys, this seems quite possible. 'You can't try to control them. Just get them on your side.'

Mr Gray certainly seems to have won them over. Whereas most seaside resorts resign themselves to sedate bingo nights during the week, Trevor has created a live event in which the audience, not the stage act, takes control. His pragmatic mix of acts, ranging from the passable to the plain embarrassing, sells about 600 tickets a week. Seats have to be booked in advance when the contest reaches the semi- final and final.

Considering the extent to which the spectators exert their power, very little damage is done. Last week someone throw an ashtray - a practice which was quickly discouraged. But Trevor is planning to have a barbed wire barricade across the stage for the semi-final, just in case. Tonight the security guard is worried about the quantity of potatoes aimed at performers. 'These ones could be dangerous - they're hard,' he explains, running up to one of the tables and hauling out a culprit.

The intended victim was a vocalist, Zara Gill, offering a throaty rendition of 'Non, Je Ne Regrette Rien'. Two young men with loud-hailers shout: 'You should do] Get lost] Sod off]' She plods bravely through the verses but her words are obscured by a barrage of verbal abuse worthy of a Millwall away game. The only difference is that tonight's perpetrators are not just frustrated male fans channelling their hostility. The age range seems to be seven to seventy, and there are as many women as men.

'The women here love it,' observes Jonathan, 25, a hairdresser. 'They don't get hassled like they would in night-clubs and they can be as aggressive as they want.' At one table Jo and Mia, pretty, delicate-looking teenagers, pour out a stream of invective when a scantily dressed dance troupe performs a routine reminiscent of Pan's People. 'Get off, you tarts]' shouts one of them. 'Just because you can get the men looking at you - complete tarts]' Their voices rise to shrill screams. They stand up and hurl handfuls of jelly beans at the lycra-clad figures. The act concludes with a bare-chested youth in black satin pants writhing around on the floor to the Boomtown Rats' 'I Don't Like Mondays'. 'Are you a raving poofter or what?' shouts a man. The girl dancers have exchanged red slinky outfits for long Laura Ashley dresses and now pirouette gracefully to the song's final verse. 'Show us some tit then,' yells the same young man.

Bawdy but relatively inoffensive, the show offers some sort of emotional release. 'These people would never normally behave like this,' says Terry, a 28-year-old social worker. 'This is their chance, after spending all day in the office being civilised.' Richard, 40, a Brighton civil servant, waves an enormous inflatable toothpaste tube in the air. 'Even my kids say I'm completely stressed out,' he explains. 'So I come here because it's more therapeutic than exercise.'

There seems to be no shortage of performers ready to submit themselves to this ritualistic humiliation. Budding karaoke champions quake in fear at the prospect of appearing, but still put their names on the waiting list (currently at the 100 mark).

'I don't take it personally when they boo me,' says Terri Wylie, after she has been hissed off the stage. 'I'd come back again,' she adds, apparently grateful for the experience. Contestants know that endurance, not star quality, is the key to success. As Trevor Gray says, if you can play Worthing on a Monday night and survive, you can play anywhere and excel.

Star Search heats tonight and on 8 and 15 August, semi-final 22 August, final 5 September, at Worthing Pier's Pavilion Theatre, 8pm.

(Photographs omitted)