Killer bee movie: Australian film saboteurs Double Take have rewritten the script for the classic turkey The Bees. Dominic Cavendish cringes in the aisles

Everyone laughs at fart gags,' insists Sally Patience. 'Critics may just go, 'Oh, it's toilet humour', but you know that they've secretly been enjoying it.' Both she and Des Mangan, who form Australian comedy act Double Take are upfront about the nature of their material. They know their fart gags get laughs. But then they are unusually lucky. Their uninhibited outpourings provide the 'soundtrack' to one stinker of a movie.

The pair have just transported Alfredo Zacharias' 1978 turkey The Bees from Melbourne to the Prince Charles cinema off London's Leicester Square. Shot in Mexico in two weeks, it is a blatant rip-off of that year's The Swarm, and has all the hallmarks of a low-budget 'disaster' movie: risible special effects, botched editing and irredeemably wooden acting.

Double Take's show is 90 minutes of non-stop sabotage. Standing at the back of the cinema, mikes in hand, they lip-synch with the stars, turning the predictable plot- line into a surreal war between humans and performing Mexican bees.

Feeble gags fly thick and fast. Tania Hide teams up with New York private eye Jack Doff to stop the bees that have killed her husband ('I'll get over the mourning period. Once I get into the afternoon period I'll be fine.') The farting noise Jack's plane makes on landing at the scene of the swarm is repeated a few minutes later when Jack and Tania get physical. Yet however imbecilic the remarks Mangan and Patience put into the character's mouths, they still run rings round the original script. They exploit the actors' deadly seriousness by suggesting both their subservience to the plot and a gloomy realisation that the film sucks. The best moments are deadpan exchanges: 'What's the matter Jack?' - 'I'm about to eat some plastic fruit'; 'Shit, I nearly forgot my lines there for a minute,' or, during an appallingly choreographed fight sequence, 'Throw me out of that window, there's no glass in it.'

The simplicity of the humour belies the effort behind it. According to Patience one Australian TV boss hired a team of 12 to attempt a similar project, 'but they just couldn't manage it'. She is modest about her own contribution to the show, explaining that Mangan writes the script, while she combs through looking for continuity errors ('boom mikes coming into view or horses getting stuck in haystacks'). They then spend hours in front of the video, getting the timing down to a split-second. They've been working together for five years and have become so attuned to B- movie production values that they found themselves automatically reworking the CNN reports during the Gulf War.

Despite the potential for political satire they favour 'totally crap films', as Des puts it. Before The Bees there was Hercules Returns (which they are to release next year). Their classic, Astro Zombies, Ted V Mickels' 1968 loser, made it to the 1987 Edinburgh Festival. 'That was about a scientist who is commissioned by the Australian government to produce the perfect stereotypical Australian male,' explains Patience. 'Someone who could fart, belch, spit and spew all at the same time.'

Double Take have been accused of sexism and homophobia in their time, but Patience refuses to apologise. 'I've had a lot of shit piled on me for doing sexist humour. Australia has become so conservative over the last few years. With the safe- sex mentality has come this demand for safe comedy. We were called homophobic because of one line when a woman runs out of a caravan and screams, 'All bees are poofters'. That's not our view but there are actually people in Australia who would believe that if you said that to a swarm of killer bees, they'd piss off.'

Standing at the back of a cinema performing to American schlock may not get Manghan, 31, the script-writing job he wants or establish Patience, 27, as a great comic actress, but they're not concerned. Their sights are set on lower things. 'Wouldn't it be great to do a TV mini-series composed solely of all the dreadful films well-known actors have ended up in? You could call it What a Way to Go.'

'The Bees' at Prince Charles Cinema, London WC2 (071-437 8181) to 24 Dec

(Photographs omitted)