Perhaps Asda's most unpopular initiative, however, was to try to cut costs by withdrawing a Christmas discount offered to the group's 140,000 employees. Asda has continued, nonetheless, to insist it is not anti-union. One internal document proposes increasing employees' productive time by cutting back on lavatory breaks, putting pressure on shop stewards to spend less time on union business and creating channels for communicating with employees without the involvement of the GMB general union. Asda managers, it is claimed, have adopted a softly-softly approach to marginalise unions under a so-called "chip-away" strategy. That, in turn, has spooked Wal-Mart into thinking it has to stop being the bogeyman of American business and try to make itself, at the very least, less visible. That lower-profile approach has been employed at Asda, Wal-Mart's British subsidiary, which has in large part avoided hitting the headlines, while attempting to import simlarly controversial tactics into the UK.

The film charts one particularly striking instance in which a community slammed the door on Wal-Mart - the middle-class, predominantly black Los Angeles neighbourhood of Inglewood, which voted against admitting the chain in a referendum last year despite a long and costly campaign by the company. Certainly, Mr Greenwald would argue that the Wal-Mart economic model is by definition unsustainable. He calls it a "suicide economy" and cites a multiplicity of people in his film -- Republican small business owners who feel stifled, residents of gated communities who resent Wal-Mart changing the land-use rules and moving in next door - who might otherwise be moved to applaud capitalist enterprise in action. What makes the paper so powerful is that its lead author, David Neumark of the Public Policy Institute of California, has been sceptical of union-led "living wage" campaigns in the past. The company denies this, of course, but a newly published academic paper argues in scientific fashion that Wal-Mart stores reduce employment by anywhere from 2 to 4 per cent in communities and depress local wages by as much as 5 per cent. First because of its size: with more than 1.3 million employees and revenues of $285bn this year, it is larger than quite a few countries.

And second because the very thing that makes it so attractive - low prices on everyday consumer goods - may be the very thing that is strangling the communities it serves. There's so much wrong with this company, I wouldn't even know how to begin." Such incendiary accusations aside, Wal-Mart is an extraordinary phenomenon in American society. "You won't ever find these policies in a Wal-Mart handbook, but every single manager in this country is taught how to do these things," Mr Nicholson alleges "If you learn to do them well, you are promoted If not, then they find a way to force you out... It concerns a former company executive, Weldon Nicholson, who describes how he was ordered to bust attempts at union organisation, "ignore" the existence of undocumented immigrant cleaning crews, make campaign contributions to local politicians who indicated their opposition to new Wal-Mart projects, shave hours off employees' time-cards, and inform workers about government healthcare programmes so the tax-payer, not the company, would meet any medical costs. One of the film's most powerful sequences has, however, prompted no comeback to date from Wal-Mart. Depending on your point of view, this is either an attempt to nitpick the film to death, or an illumination of Mr Greenwald's slanted view of the company. Wal-Mart argues first that it cannot have been responsible for the closure, because its store did not open until after the hardware shop closed, and second that it cannot have deterred hardware businesses because another one sprang up on exactly the same site shortly afterwards and is still going.