Back at the end of July, passers by on the Royal Mile in Edinburgh were confronted with a giant inflatable green dragon and a display of mediaeval pageantry in which a procession of agitators attempted to slay the beast. The dragon was emblazoned with the words, 'PUBLIC AND PRIVATE OWNERSHIP' on its front, and 'CORPORATE GREED' on its back. Some of those attempting to usurp it were tattooed with the word 'NATIONALISATION'. It looked like a satirical cartoon made flesh and acted out in a display that resembled something between a mummer's play and an episode of Horrible Histories.

This was By leaves we live...not by the jingling of our coins, the latest processional intervention by Zoe Walker and Neil Bromwich, who have previously made weapons of happiness out of the pink blow-up artillery of Love Cannon (2005), which brightened the skies by firing pink balloons. This new intervention is inspired by an illustration found on a Northumberland Miners' Association banner from 1924 as well as 19th century anarchist pamphlets. It acted as a trailer of sorts for The Dragon of Profit and Private Ownership, in which the dragon lays dormant until the end of Edinburgh Art Festival in the Old Town's suitably historic Trinity Apse building, having hot air blown up its arse all day long. A bunting strewn booth shows footage of By leaves we live… on a series of monitors.

The event itself subverted civic spectacle on a par with some of Jeremy Deller's parades, and also taps into a very real democratic need for collective participation in artistic acts rather than merely being passive observers. This recalls some of the outdoor spectacles of Welfare State International, as well as the early capers of Ken Campbell, Jeff Nuttall's adventures with The People Show and Albert Hunt's experiments with the Bradford Theatre Group. Like such forebears, Walker and Bromwich's intervention is a comic revolutionary provocation in which we can all join in, slaying dragons as we go.

Trinity Apse Church Nave, until 27 Aug, free.