'America has defined itself in the early 21st century as a cowboy state. George W Bush has hyperbolically expressed all the cowboy mentality the world holds of America.'

So says Oliver Stone from Louisiana, three days before he starts shooting W, his serio-comic look at the 43rd president of the USA and one of the most controversial figures of our time.

Sold internationally by QED International, W looks at the president from the age of 20 to 58, after the start of the Iraq war. Although the time periods will be mixed up throughout the film, it is, says Stone, a 'three-act film' starting with Bush as a young man 'with a missed life', then his transformation and 'an assertion of will which was amazingly powerful' as he emerged from his father's shadow, and finally his invasion of Iraq. 'He achieved what his father did not by getting re-elected,' says Stone. 'What he does with that is the question.'

Stone says the tone of the film is 'ideally in the vein of Network or Dr Strangelove. I was a young man when I saw Dr Strangelove and it still stays with me. It took a very grim subject and turned it into a serio-comic story and it worked. So those would be great models for the movie to live by.'

Stone and his writer Stanley Weiser developed the project in early 2007 and Weiser worked on the screenplay while Stone prepared Pinkville at United Artists (UA). But when UA pulled the plug on Pinkville, Stone immediately switched his attentions to W, securing Josh Brolin to play the title character in December.

'He is one of the great characters of this time and I think he has had enormous impact on the world and our generation as well as future generations,' says Stone, who points out that Bush's popularity in America's heartland remains enormous.

'I am sitting in the Bible belt and frankly there is a lot more affection for him than you think. Americans voted for him in quite big numbers in both elections. As someone told me the other day: he liked Bush because he doesn't try to pretend and try to be something he isn't; he tells it like it is.'

Casting the cabinet

Joining Brolin in the cast is a rich ensemble of well-known movie actors including Elizabeth Banks as Laura Bush, James Cromwell as George Bush Sr, Ellen Burstyn as Barbara Bush, Jeffrey Wright as Colin Powell, Thandie Newton as Condoleezza Rice, Scott Glenn as Donald Rumsfeld, Toby Jones as Karl Rove and Ioan Gruffudd as Tony Blair. Richard Dreyfuss is in talks to star as Dick Cheney.

'It's about his inner workings and his people,' says Stone, who adds that Saddam Hussein is characterised in the movie 'in a pretty funny way'.

Meanwhile Stacy Keach plays a composite of evangelical ministers, including Billy Graham and Jim Robison, who influenced Bush in his conversion to Christianity.

'Richard Nixon very much invoked the silent majority and the friendship of Billy Graham, but Mr Bush has taken (religion) further than ever (into government) and so we have to dramatise that,' says Stone. 'We must on the surface take his conversion seriously. It is the centrepiece of his change. At the age of 40, he was a drinker and he changed quite radically over a period of four years, so something happened to him. Whether he became the same person on the other side of the coin is an interesting issue and I examine that too. Some of the characteristics, however, never disappeared such as the temperament, the anger and the impatience.'

The film, however, won't be an intense three-hour drama like Stone's 1995 biopic of Richard Nixon. 'It's not as psychologically heavy,' says the director. 'I don't perceive George Junior as troubled or as psychoanalytical as Richard Nixon although there is a remarkable similarity in their presidencies. Nixon was more ambitious in scope and time. This is more of a souffle. You have to laugh a little bit at (Bush's presidency) because there are so many sad things in this. It's tragicomedy.'

Stone seems more blase than he was earlier in his career about criticism. He is determined to make films which attempt to understand events and people from this era.

'I am still trying to understand America myself,' he says. 'I was born the same year as Bush and we went to Yale at the same time. I am of his generation and these are questions that concern me. As you know from my body of work, I love this country, I love what it stands for and what it's done. At the same time I have been critical of many of its policies publicly and in my films and I've taken my share of heat for that. I have been so trashed for JFK, Nixon and others that I just pass on and say, OK, I am just going to do my perception of what happened. I am flitting through my time and all I can do really is to reflect what I see of that time.'

Inside the president's mind

Assumptions are that Stone and Brolin will be critical and mocking of Bush, but Stone begs to differ, arguing the actor is putting aside any personal political differences in an attempt to understand the character.

'Josh is professional and is trying to understand how (Bush's) brain works,' says Stone. 'Whatever you say about him as a human being, he has had his share of problems and obstacles to overcome. In the south, one of the reasons they like him is for his sense of family and his commitment to his faith. Those factors make him a very decent human being in the eyes of many people. Tony Blair for one fell for him and liked him a lot. Blair was a very sophisticated man who had traveled the world and look what happened, he was a big fan of George Bush. In fact, he has since declared his Catholicism.'

Meanwhile Stone is pleased that Lionsgate has picked up rights in North America (as well as UK and Australia) to the film after a unanimous rebuff from all the major studios.

'It's ultimately better for the film because they won't be as pressured or intimidated by the corporate concepts,' he says. 'It was always a very good script but people would rather not be bothered. It is easier not to be bothered: 'Why should I make it because I work for a giant corporation and maybe in three months' time someone is going to come down and nail me for it.' It's really sad. It's a risk-free environment now. It used to be an environment where the studio chiefs were bosses and made up their own mind.'

Instead, producers Jon Kilik, Moritz Borman and Bill Block assembled a complex financing structure for the $25m film consisting of Block's QED, Australia's Omnilab Media, China-based Emperor Group, Thomas Sterchi's Condor Films and Hong Kong's Global Entertainment Group.

Lionsgate plans to release the film on October 17 to coincide with the last few months of Bush's presidency, and Stone is confident that international sales will be strong on the back of fascination with the controversial Bush.

'We will do better overseas than people think. You think he will be done in January. Bullshit. His influence will be felt for many years. We will never forget him. He is not going to be a forgotten president.'