Australian great Jack Thompson opens up about the hitherto shrouded-in-mystery epic Australia, and why maverick director Baz Luhrmann has resorted to testing and re-testing the film in America's red states.

"The film is under tight wraps." With that one dry utterance, you're reminded of why local great Jack Thompson has had a mortgage on iconic laconicism for so many years. Australia - Baz Luhrmann's hulking epic, which doffs its hat in style and largesse to pictures such as Gone With The Wind and Casablanca - is almost a national security issue, so tightly guarded is the film's content. At the time of interview, Thompson hadn't even viewed a rough cut of the film. Ironically, the only ones who have beheld Luhrmann's opus are a group of American mallrats. "Yeah mate, no one in this country has really seen the film - so we're in the same boat. Some fortunate Americans were invited as a test audience in the so-called 'middle states'. They haven't even seen the final film, just an earlier version."

So what does Luhrmann hope to ascertain from these curious off-shore screenings? Like many questions, this one sends Thompson whistling through his memory vaults - and as always, he comes back with an anecdote crusted with wisdom, and framed with his inimitable brusqueness. "Mate, the first time I became aware of someone doing that with a film was way back with Apocalypse Now," Thompson replies. "The venue was the Cannes Film Festival, and I remember that they showed the film for the first time with three different endings. Every member of the audience was given a survey sheet, and the audience told them what they found appealing."

It's hard to gauge from Thompson's measured yet sonorous tones whether he's sniffing at the irony inherent in this tale - that is, one of the most audacious and uncompromising films ever made being subjected to committee filmmaking by audience vote. Thompson wouldn't be the first actor to be dyspeptic about the testing process that is now back in vogue - many artists are dirty on soliciting the judgments of the masses. "Oh, it's a good idea in principal," Thompson offers sincerely, swiftly adding the caveat, "but it depends on how much notice you take of it, and on how you allow it to influence you. It's pretty powerful sometimes. It's probably silly to ask the audience to decide how you should end the picture. On the other side of it, you've got someone like Coppola, who was saying, 'There you are! Take your pick - any of these endings work for me. Now let me know what works for you'."

"The film is being made for a huge audience," Thompson continues magisterially, quashing suggestions that the broad-stroke Australiana is aimed squarely at the American box office. "It's for all of Australia, all of America, all of the UK, and all of the English speaking world really, and probably beyond that with subtitles. So the question that is being asked when you present to a test audience is, 'Does this film transcend its parochial quality as an Australian film?' The answer thus far is a resounding yes. It certainly does. That was clear when I first read that lovely script some two years ago. Under those circumstances, it's a legitimate test, because when you've been making a film like Australia for the five years or more from its inception since Baz came on, you are very much focused on the film. It's hard for you to determine whether an audience in Middle America or Britain or China is going to understand what this is about. The fear is that this might be peculiarly and particularly Australian. I know that it isn't."

So, did Australia feel every inch the epic on-set? "That it did, mate," Thompson replies. "This was filmmaking on such a huge scale. I'll never forget going out into the country, and they'd built this extraordinary homestead and yards and blacksmith shops. Everything was there - this whole world plucked straight from the late forties. So for me - not for the younger fellas on set - it was like a time machine. I reminisced about the aboriginal stockmen who I'd worked with in the past, the horses, that extraordinary landscape, the dust.it was just wonderful."

Thompson had the honour of skirting the traditional casting process and was offered the role of elder statesman Kipling Flynn directly by Luhrmann himself. Does Thompson still have the hunger to keep on fighting for roles that he's passionate about? "Oh, I hope to go on playing interesting roles in any sort of features with directors and actors as yet unknown," he replies. "There are always young actors and directors coming up, and writers who put together a script. If it's of interest to me and they have a suitable place in the script for a man of my advanced years, then I would be delighted. I enjoy the process of filmmaking. I'm an actor, mate, and as long as I can stand up, I'll keep doing it."

Australia is released on November 26.