Still, it’s a rarefied world that most of us know little about. Certainly that was the case for Madden’s star, Jessica Chastain, who previously worked with the director on his 2010 film The Debt. Here, she plays Elizabeth Sloane, a ruthless, workaholic lobbyist who gets embroiled in the debate surrounding gun control.

“No one really says, ‘I want to be a lobbyist when I grow up,’” she says. “You never really hear of that profession.”

Chastain started her research by Googling all she could, beginning with the work of jailed lobbyist Jack Abramoff, who was sentenced to six years in federal prison for mail fraud, conspiracy to bribe public officials and tax evasion.

“He would connect his clients with politicians and the politicians would get trips to Scotland, golf trips… there was a lot of grey in what he was doing,” says Chastain. “After him, [former US president] Obama restructured the whole lobbying system.”

Arguably, Obama didn’t do enough. Chastain went to Washington on a fact-finding trip to mingle with the great and the good, and crucially met 11 female lobbyists. Only one in 10 lobbyists in the US is a woman, and it took some convincing to persuade those she met to talk to her – with some uncertain of her intentions (although they only have to look at the two-time Oscar nominee’s CV to see it’s packed with integrity).

She also met congressmen and senators. One particularly eye-opening fundraiser saw her witness one corporate representative address a lobbyist by saying, “We’re interested in California. Which up and comers should we support?”

“I was watching and I was like, ‘Oh my gosh, they’re asking because they need something in California and they’re trying to figure out which politicians, which up and comers, they can basically buy or support’.”

The storyline of Miss Sloane – the script was written by first-timer Jonathan Perera – is fictional and “floats free of actual circumstance”, as Madden puts it.

“It should be pointed out and remembered that the absolute core of the film is a very, very extraordinary example of that breed, who is pushing the envelope as far as it can go and works at the boundary of ethical and unethical behaviour in order to pursue an agenda.”

Sloane comes across as a win-at-all-costs character with little by way of scruples. “She’s an immensely complicated figure,” says Madden. “Extremely flawed by any objective standards. Whatever emotional life, let alone spiritual life, she might once have had has been locked away in some compartment…she’s long ago thrown away the key and doesn’t really have any access to [it]. Which makes her very intriguing.”

Such is Sloane’s nature, her idea of a relationship is hiring a gigolo (and she becomes very upset when her regular man is replaced). “She needs to be in complete control,” says Chastain.

“She says it’s about making sure you surprise and they don’t surprise you; it’s always about being one step ahead of another person. And in an equal relationship, you can’t be that. But when you’re paying the other person, you get to say what the game is, you hold all the strings.”

While it feels like Sloane might be a distant cousin to the CIA operative Chastain played in Kathryn Bigelow’s Zero Dark Thirty, who similarly devoted her entire life to her career, the actress feels this is a study in addiction.

“I’ve found with a lot of addicts – whatever behaviour, whether its drugs, food, sex, alcohol, work…you’re filling an emptiness inside of you. Everything with Elizabeth is finding the high of the win. She doesn’t take on this case as a noble cause. She does care that people are dying. But for her, it’s the impossible win. The unbeatable thing.”

After rejecting a lucrative offer to fight for the pro-gun lobby, Sloane resigns from her firm, takes four of her colleagues and joins the other side – campaigning for gun legislation. If anything is the impossible win, it’s this.

“The issue of firearms regulation itself remains a baffling one even when you get to the core of it,” says Madden. “The paradox is, ‘How is it that the majority of the American public are in favour of increased background checks but this never, ever, ever gets through into any meaningful legislation?’”

Indeed, after so many horrific massacres in the US, from Columbine to Sandy Hook, “baffling” doesn’t even begin to cover it. While Miss Sloane isn’t a strictly about the gun debate, it uses the issue smartly as a way to discuss the inherent corruption on Capitol Hill.

“What I love that the film explores,” says Chastain, “[is that] a politician can’t properly serve the people they represent because their focus and their priority is keeping their seat and office.”

Again, the actress saw this first-hand when she was in Washington. Politicians attended three fund-raisers a day – breakfast, lunch and cocktail/dinner events – simply to raise money and support to help keep their spot.

“It doesn’t matter that society says, ‘We want this!’” adds Chastain. “[It’s about] who is giving them the money? And that person, or that corporation, is now dictating the law. So that for me was really fascinating in the film and I hope it leads to a discussion.”

Released in the US in November, shortly after the end of one of the most remarkable elections the country has seen, Miss Sloane grossed just US$3.5 million. “Sometimes these movies arrive in a circumstance you can’t completely predict,” shrugs Madden.

Perhaps a film that dug deep into the corruption in Washington was too much for audiences – or perhaps it was impossible to distract them from the nightly news.

“People stare with horrified fascination at everything,” he says. “And I do think the film is quite an exhilarating ride through that process.”

Miss Sloane opens on February 16

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