Pablo Larraín looks affronted. I've just asked the Santiago-born director if his trio of movies set in Chile in the 1970s and '80s - Tony Manero (2008), Post Mortem (2010) and the latest, No - were inspired by the current retro-thirst for revisiting these decades. "Oh, no!" he cries. "I'm more selfish than that. It's the ending of a trilogy of work that is larger than just fashion [for the past]. I think the story would be interesting if it were happening in the '80s or '90s or now. It's an amazing story. It's real."
The Academy of Motion Picture Arts and Sciences agreed, with the Chilean nominee making the five-film shortlist for the best foreign-language film for this year's Oscars. Loosely based on The Plebiscite, the play by Antonio Skármeta, No is set in 1988, at the tail-end of the brutal 15-year regime of General Augusto Pinochet, which saw - according to human rights organisation Amnesty International - more than 2,000 people killed and several thousand more tortured by military forces.
Pinochet staged a referendum - a "yes" or "no" public vote - designed to gain a further eight years in office. Against all the odds, the "No" campaign, waged via a series of television advertisements, secured 55.98 per cent of the vote, leading to Pinochet's resignation.
Just 12 years old then, Larraín still has vivid memories of living through this remarkable period in his country's history. "What I remember is that when the campaign was on, everybody was looking at it," he says. "[There were] no cars in the street. The country stopped, [and was] just watching TV. There was no internet. Everything was through TV."
With the "No" side offered a nightly 15-minute TV slot to persuade voters to oust Pinochet, the film follows advertising executive René Saavedra (Gael García Bernal) as he constructs one of the most important advertising campaigns in the history of television. Using jingles and crude multicoloured graphics, it was hardly sophisticated. "Now we can laugh about it," says Bernal. "It was done with the rudimentary means they had in those days. But it was a very honest, hopeful and delicate thing to involve themselves in."
The way he sees it, it was the spirit of youth that drove the "No" campaign. "It was something young - [the idea was] 'Let's do something, let's promise the sun is going to come out in Chile after Pinochet leaves power'. And it's a very fair statement. In those days, Chileans were incredibly depressed. Chile was just a grey country. The culture had been chopped down. All the fabulous poets and singers that Chile had were completely stopped by the dictatorship. And all of a sudden these guys said 'Let's make a rebirth of Chile'."
The Mexican-born Bernal, now 34, was three years younger than Larraín - but even then he was aware of the situation in Chile. Living in Mexico City, the son of two theatre actors, he was regularly in contact with the children of political exiles from Chile. "I knew about Pinochet [and life there]. You had no future. You had to leave, to escape."
Bernal is no stranger to politics. Prior to studying acting in London at the Central School of Speech and Drama when he was 17, he took part in the peaceful uprising in the state of Chiapas in support of Subcomandante Marcos' Zapatista rebels. Then, at the 2003 Oscars, he spoke out against the Iraq war, the year before he played Cuban revolutionary Ernesto "Che" Guevara during his formative Latin America road trip in The Motorcycle Diaries. So it's no surprise when he becomes animated when we start talking about the electoral process.
"We all have to be cynical with elections," he says. "Not democracy, [but] with elections. It's a muddy, perverted process. Even the candidate you want to win will end up trivialising, downsizing the issues that are at stake. It's a disgusting, exhausting process. But the real democracy happens in everyday life - where you build something, create something, speak out. That's the best form of democracy. It's like a football game - the best team doesn't always win. You have to score the goals."
Fittingly, both Larraín and Bernal have been leading their own charge during the publicity drive for the film, joining forces with Amnesty International to back their "No to Impunity" campaign, which is pressing for governments in South America to confess to their murky pasts. "There is a lack of justice still," says Bernal. "Pinochet, for example, never went into a court house. He was never tried. He died [in 2006] with millions of dollars in a United States bank account."
One of the most interesting aspects of No is the way Larraín uses archival footage - from news reports of demonstrations to celebrity endorsements of democracy (including Jane Fonda, Christopher Reeve and even Richard Dreyfuss, fumbling his way through some Spanish). He seamlessly weaves the material into the film by shooting scenes featuring Bernal and the rest of his cast on a U-matic, the old-school video camera used in the 1980s by most news programmes, to ensure it all matched up.
Yet however well Larraín joins the dots, this drama with elements of satire has still come in for some criticism - with some carping that No over-simplifies events. On Twitter, Chilean politician Francisco Vidal wrote, "To believe Pinochet lost the plebiscite because of a TV logo and jingle is not to grasp anything of what occurred." Larraín retorted that "the movie is just a fragment", arguing that he never wanted to simplify the campaign. And it has been pointed out that the film also, somewhat crucially, fails to recognise the efforts of the anti-Pinochet movement to register 7.5 million Chileans to sway the vote.
Adding further spice is the fact that Larraín comes from a family with right-wing links; his father was a senator and president of the chief pro-Pinochet party; his mother served as a cabinet minister in Chile's current conservative government. Not that this ever stopped him addressing his country's bleak past. Tony Manero used a Saturday Night Fever-obsessed psychopath to comment on the cruelty of the Pinochet regime, while Post Mortem dealt with a mortician who encounters the corpse of President Salvadore Allende, who was overthrown by Pinochet in 1973 amid an American-backed coup d'état.
Understandably, gazing back at Chile's bloody history has left Larraín spent. "I've been doing movies all set in the past and it's exhausting," he admits. "I'm dying to shoot in the street, to go out and make something with real life. I'm over the period. That's it for me."
Indeed, he's just produced a comedy, Sebastián Silva's Crystal Fairy, which stars Canadian actor Michael Cera ( Juno; Superbad) as a boorish American tourist travelling through Chile. You can hardly blame him for wanting to smile.
No, tomorrow, The Grand Cinema, Elements Mall. Part of the HK International Film Festival. On general release in May