In all the flailing post-Oscar babble, there was much talk of Best Supporting Actress Melissa Leo's 'F-Bomb' and Christian Bale misplacing his wife's name, but little mention of Charles Furguison's far more provocative acceptance speech: "...I must start by pointing out that three years after a horrific financial crisis caused by massive fraud, not a single financial executive has gone to jail and that's wrong."

Charles Ferguson and Audrey Marr's win for Inside Job, a stark investigation of the 2008 financial crisis, is yet another confirmation that polemical documentaries (as opposed to the 'inspirational true stories' and penguin-fests that often dominate this category) have matured and are entering mainstream consciousness.

In the past decade, political documentaries have become big business, starting with the surprising critical and commercial success of Bowling for Columbine, winner of the 2002 Oscar. Spurned on by the affordability of video and video editing software or the new platforms of the internet, a small industry of left-leaning docs sprang up out of nowhere; framing themselves as a counterbalance to the misinformation propagated by the Bush White House and Fox News. Some were impassioned comments on the abuses of the times (Orwell Rolls in his Grave) while others seemed downright paranoid (Loose Change).

But although these films were generally more rigorous and journalistic than Michael Moore's pedantic ramblings, they never seemed to break out of their comfortable liberal fan base. Mail order distribution, straight-to-DVD packaging and amateurish production values didn't do them any favours either (the otherwise excellent Outfoxed scored big time interviews but its graphics seemed to be fashioned out of mid 90s office clip art). In short, they weren't winning the information war.

And even worse, in the lead up to and aftermath of the 2004 election, they became increasingly partisan, resorting to muckraking rather than actual journalism (Farenheight 9-11) and potential oversimplifications to get the message accross (An Inconvenient Truth). This is not to say that they were wrong in their stances, but just that the smug glow of the moral high ground made them seem about as 'fair and balanced' as Murdoch's TV counterparts.

That's why in 2007, it was refreshing to hear two more measured voices emerge out of the cacophony; Alex Gibney and Charles Furgison stood out by making their arguments from much firmer, less obviously ideological ground. Gibney's Taxi To The Dark Side (which bagged the Oscar that year) used the story of the torture and murder of an Afghan taxi driver by the US military to raise questions about the morality of torture in a post 9-11 world. The strength of the story was that even if you disagreed with his conclusions, the problems it raised couldn't be so easily swept aside.

Along similar lines, Charles Ferguson's documentary No End In Sight brilliantly sidestepped the usual debates about the justice or injustice of the Iraq War: even if the war was the right thing to do and bringing democracy to the region was the genuine goal, it was utterly botched in its execution. As Ferguson points out, the invasion may have been meticulously planned but little consideration was given to statebuilding. The reconstruction of Iraq was essentially run by children (literally, in fact, implemented to a large degree by 20-something college graduates with family connections) and under the mismanagement of Paul Bremer, created an ideal environment for an insurgency to form.

Four years later, both filmmakers have turned their sights on Wall Street with two films arriving in UK cinemas this week.

Gibney's latest film Client 9 again finds a back door into the issues though a targeted, real-life fable: the downfall of former NY Governor Eliot Spitzer. Spitzer was a driven NY district attorney who made great strides in curtailing the reckless behaviour of Wall Street executives as it (frequently) veered into criminality. If given enough time he could have pushed though historic regulation of Wall Street and, before Obama's meteoric rise, might have been "the first Jewish president". His "white knight" persona was shattered when it was revealed that he had been using the services of the same high-class prostitutes as his Wall Street enemies.

As a character study, Client 9 is a fascinating portrait, but it's also a crash course in political assassination. It's clear from the great lengths and unorthodox procedures used to name and shame Spitzer that he was deliberately "taken down" by his enemies (which include a baffling Republican swinger with Nixon's mug tattooed on his back), and Gibney stops just short of accusing specific Wall Street players including AIG's Hank Greenberg.

If incompetence and inexperience were the prime accusation of Ferguson's No End in Sight, Inside Job ups the ante to outright deception and criminal fraud. Opening with a quick detour to Iceland's shambolic experiment with deregulation, Ferguison dives straight into Wall Street accompanied by a wincing Peter Gabriel anthem worthy of American Psycho.

This is a rare documentary designed for the big screen, whether it's sweeping helicopter shots of corporate HQs or zooming in on the craggy faces of economists as they squirm in their seats. While the graphics in No End in Sight more closely resembled a First-Person Shoorter menu, here they are clean and blissfully simple, making quick work of some notoriously complex financial products.

Ferguson roasts the careless and arrogant financial institutions, the incompetent regulators and especially the [de]regulators Alan Greenspan, Robert Rubin and Larry Summers. Although other accounts of the crisis, like Bethany McLean and Joe Nocera's All The Devils Are Here go after Fannie Mae, Country Wide and U.S. Housing policy as well as Wall Street, only Ferguson seems to have noticed the conspicuous influence of academic economists on the proceedings - many of whom were financially compensated by the Wall Street firms they defend in their writing.

The only potential weakness of this film is, ironically, Ferguson's certainty. Occasionally, you'll hear Errol Morris, sounding incredulous behind the camera, but Ferguson often interrupts his subjects with... "You can't be serious!". Clearly some of these experts are not used to being questioned. Ferguson also stops just short of naming specific criminal wrongdoing, although in interviews he has stated that he can't imagine the crisis being possible without massive fraud.

While Inside Job most certainly calls for regulation it also, not so subtley, hints that Wall Street executives might be held to the fire if, like Spitzer - who appears in the film - their use of prostitutes were examined.

Both films are extremely polished and sophisticated vehicles of their their messages and should appeal to a wide bi-partisan audience but, it already seems clear, that neither of these call to arms will be acted upon. It's a shame that neither film spends enough time grilling the media for glossing over these twin outrages, because its the same media that is failing to capitalize on the fuss these two filmmakers are kicking up.