Over the eight days of Volcano!, London's underground film clubs will come together at sites scattered throughout the metropolis.
In a film culture dominated by a crippling lack of imagination and a shopping aisle multiplex mentality, the London underground's brand of mixed media provocation is more vital than ever before.
To a certain extent the idea of "underground film" still lives in nostalgic thrall to its Sixties influences, to a pre-punk DIY aesthetic that sought to explore film as a personally expressive medium and to retrieve it from industrial models of film production and consumption.
I asked Duncan Reekie, a film-maker and member of the Exploding Cinema collective, which has been active now for six years, how he would define "underground".
"You can either define the underground as the early stage of the avant- garde or in terms of its content," he said, "in as much as it's sex and drugs and excessive or spectacular degeneracy.
"But I'd argue that it's neither of those things. I think it's got more to do with a different conception of cinema based upon a kind of popular idea of culture or folk culture, like pubs, circuses or the music hall. The roots of cinema lie in that bawdy, fairground, carnival type atmosphere."
It is a part of the strength of the London underground that it has largely taken on this early-cinema idea and throws together open-access film screenings with performance, readings, live music and all manner of site-specific mayhem.
With the increasing prominence of experimental visual artists in the club scene, as well as the ubiquity of the moving image in gallery spaces, cinema has, it seems, well and truly expanded beyond its conventional institutionalised spaces. This expansion, Reekie says, grew out of the frustration with "independent" cinema that lies behind the Underground ethic.
"The idea is to break down the mystique of film-making," he says. "There's no mechanism between the film-maker and the audience. Most of these ideas come out of the fact that we were film makers back in 1991 and were incredibly frustrated by the fact that there was no audience for our films.
"When we tried to approach people at funding organisations or in institutions the answer would routinely be that this is `difficult' work - it's avant- garde or experimental, you can't expect ordinary people to understand this work.
"Eventually we just said `No, You're wrong. And we'll prove you're wrong by putting on shows and we'll pack these shows out. This will give the lie to this idea of difficult work. Because the difficult work you're talking about is bad, nobody wants to see it and it's dreadful.'"
Reekie has a way with knock-out polemic which will no doubt be fully exercised next Thursday when he goes head-to-head with Helen De Witt, curator of the London Film-Maker's Co-op, in an onstage debate at the Lux Cinema.
This event will explore the relationship between the underground and the independent film sector, of which the Film-Maker's Co-op is an important component.
And Reekie reserves his most withering contempt for precisely this sector, which he regards as having atrophied into a self-serving, state-funded elite group whose "power of taste depends more on rejecting film makers than encouraging them.
"There are a lot of people within the independent sector who perceive the groups in Volcano! as simply models of themselves when they were teenagers, having adolescent tantrums and being rebellious," Reekie says.
"And they kind of admire us because they see themselves in that. But it doesn't really frighten them because they think that once we've stopped acting up we'll join the establishment and become their next generation. They don't understand that we don't want to become the next generation of the independent sector, we want to get rid of the independent sector."
Fighting talk, this, and bound to ruffle a few feathers in the funding sectors. As for the action of the Volcano! festival, this includes a major retrospective of the work of the Godfather of English underground film, Jeff Keen, who's been ploughing the no-budget furrow since 1959; the last night in the life of the wonderfully named underground outfit Omsk; special presentations by critic and underground anthologist Jack Sargeant and Aftershock, "a final night of spectacular decadence" when the clubs unite for a concluding full-on extravaganza.
For further information about Volcano! call 0171-582 0080 or contact the film festival website on www.backspace.org/volcano. The Volcano! box office's telephone number is 0171-582 7680