Spanning its net wide through history and across the world, The Corporation is a cynical and impassioned American documentary that relentlessly hammers home its agenda as it charts and exposes corporate power, corruption and exploitation, writes Michael Dwyer 

This is by no means a relatively recent phenomenon, the film makes clear, as it recalls the US Supreme Court decision, passed as long ago as the mid-1880s, whereby the corporation was invested with the legal status of a person.

This prompted the film-makers to invite a psychologist, Dr Robert Hare, to analyse the psyche of this individual that is the corporation. The results are, predictably, damning, describing this "person" as anti-social, self-interested, inherently amoral, callous and deceitful.

Hare is one of over 40 talking heads assembled to participate in the documentary, along with the ubiquitous Michael Moore, right-wing economist Milton Friedman, left-wing philosopher Noam Chomsky, No Logo author Naomi Klein, and Jane Akre and Steve Wilson, investigative reporters fired by Fox News.

Drawing on archival footage and masses of data, the film depicts the corporation as an operation entirely without scruples, primed to prey on human disaster for profit, on the marginalized employed in sweatshops for a pittance, on children to get them to nag their parents into buying slickly advertised merchandise.

The film makes no attempt to disguise its loaded bias as it makes its far-reaching case, mixing information not widely disseminated with much material that will be already familiar to the average viewer. As such, it is preaching to the converted, and it's hard to imagine anyone from the corporate world seeking it out unless they want to be pick up on some new tricks to boost the dividends of their shareholders.

The visual style of the film is generally drab, closer to an Open University lecture than to the free-wheeling flair of Fahrenheit 9/11, for example, and some vain attempts at humour to enliven the presentation are hackneyed, as when old film clips from Moby Dick and Frankenstein are inserted to illustrate big fish and monsters.

Shorn by 23 minutes since it was shown at the Toronto Film Festival last year, The Corporation still suffers from information overload and it could benefit from further pruning. That said, its conviction and passion remain undiminished.