IN the opinion of many knowledgeable Fringe observers, the duo of Julian Barratt and Noel Fielding are near-certain contenders for a Perrier shortlisting this year, if not odds-on to be Perrier winners. Their third Edinburgh show, AutoBoosh, is characterised by all the amiable schoolboy surrealism of their previous two, The Mighty Boosh - which earned the pairing the Perrier newcomer award in 1998 - and last year's effort, Arctic Boosh. Hearteningly, Messrs Barratt and Fielding choose to view their off-the-wall creation in typically left-field fashion. Blinkered careerists these men ain't. Rather, in their own genially

self-deprecating way, they're blokes with an artistic mission. Albeit a somewhat crazy, hazy one.

''As yet, we ourselves don't really know what this year's show is about,'' says Barratt with commendable honesty. ''We've got it to a position where it's working - in other words, it's funny - which is fine for the moment, and as it goes along we'll be able to elaborate and ornament.

''When we started off together, we were simply grateful to have a show which worked at all. Last year's show was more structured in a narrative sense, and this year's show introduces a lot of new characters and is much more dark, both literally and metaphorically, than either of the two previous shows. But none of it is a conscious process. It's not decided by design. AutoBoosh has certainly been our most difficult show to create. We've come up with three or four completely different versions so far, and we've currently got three different endings that we intend alternating between on different nights.

''The thing is that we don't actually write a script. Everything we do has evolved out of weekly nights together at a comedy club in an upstairs room at a London pub, the Hen and Chickens at Highbury Corner. We each improvise individual sketches there, using theatrical techniques that we generally stumble across in our own shambolic fashion, and then we gradually cobble all the pieces together. It's a Chinese puzzle that seems to set its own momentum, its own narrative force as it goes along.''

An overall meaning for their shows is something that the duo are content to let emerge in the fullness of time, too - in which devil-may-care regard it might not surprise you to learn that Barratt is a purist devotee of hardcore sixties jazz. As Barratt confesses: ''For Arctic Boosh, which was set in a postal sorting-office, we had a monster made out of Jiffy bags, and someone came up to me afterwards and said: 'Ah yes, the Jiffy monster - that must symbolise the tyranny of bureaucracy'. I could only look at them and say: 'Wow, does it?' ''

In contrast, following a four-month touring period which last year took Arctic Boosh to Melbourne and Sydney, it was no accident that the show ended up at the duo's ultimate artistic destination. ''It became a perfect mechanism that was beyond all need for improvement by on-stage improvisation,'' says Barratt.

Elements from that show, as well as the first Boosh Fringe outing, will feature in their first radio series in the autumn. Sadly, the six half-hour episodes will be heard only in London, on BBC local station GLR. Luckily for non-Londoners, there is now genuine interest in the Boosh partnership from TV. ''We're seriously being asked what we want to do by TV people, to the point where we're submitting budget proposals,'' says Barratt. ''We have to move on from what we do on stage, although there's no point in doing TV unless we do it right, in the way we want to. But there are only so many times you can be on a stage and say: 'Cut to a hill in windswept Russia!' and have an audience go along with it.''

Barratt's first big Fringe hit, dating from 1995, was The Pod, his two-man parody of the sillier excesses of clubland's

ambient-techno-trance generation. In animated form, it will soon be appearing as a series of short 10-minute films on BBC digital channel UK Play. Barratt's original partner in The Pod, Tim Hope, went on to become an award-winning animator,

having animated videos for people like The Beta Band.

Since its Edinburgh birth five years ago, The Pod's satirical thrust has partly been hijacked by comedy successes like Ali G. Barratt thus describes its forthcoming animated incarnation as ''recapturing its initial comic purity''. Guitarist Barratt would also like to go pure mental in a live band again. He spent much of the early nineties in a number of acid-jazz outfits, and once attained the giddy heights of being in a ska band, Little Chief, which supported Desmond Dekker on a UK tour.

Fielding's informed love of rap has led him to make a guest appearance rapping whimsically on big-beat hero Midfield General's latest album for the Skint label, the home of Fatboy Slim. It's no surprise then that the Boosh men have lots of musical plans. ''We'd like to do a concept album in the grand and pompous seventies style, with a ridiculous storyline,'' states Barratt. ''That way, we could successfully take comedy into musical venues.''

Before then, however, you shouldn't miss the barminess of the Booshers in their current venue, The Pleasance.