Diana makes controversial appearance on big screen

Naomi Watts was finally persuaded to play Diana. Picture: Getty

Still to come are Emperor, a sympathetic account of Hirohito’s actions at the end of the Second World War, and Fifth Estate with Benedict Cumberbatch bleached to resemble Julian Assange.

Yet it’s the lèse majesté of a small European co-production called Diana which has captured headlines worldwide for dramatising a two-year relationship between the late Princess of Wales and heart surgeon Hasnat Khan.

“The whole world is still fascinated with Diana,” says its director, Oliver Hirschbiegel, with satisfaction. “She had something that hardly anyone else had. Look now – is there anybody else who follows in her footsteps? No, she’s an icon.”

Hirschbiegel has form when it comes to audience-baiting. In 2004, he made the painstaking and provocative Downfall, an Oscar-nominated film, which captured the bunker mentality of another daunting famous figure. It was the first German film to show Hitler onscreen, played by Bruno Ganz as facing his final days with a mixture of rage and resignation.

As a 56-year-old German, Hirschenberg is part of a generation growing up with a tangential connection to that era. He readily admits that his connection with a princess from recent British history is far more remote. In fact, before he was approached by Ecosse Productions, whose last royal romance was Mrs Brown, he says that he knew very little about Diana, and struggles to explain why he picked up the gauntlet to make a film about the People’s Princess. He likes rebels, he offers. Especially women. “And the more I did my research about Diana, the more I got fascinated,” he says.

“Like the old-fashioned movie stars in the 30s and 40s, she had something that made her shine and be above all the others.” He especially admires her gift for projecting a compassionate image. “People who perhaps would not understand what she was saying, could watch her hold a hand, or touch a cheek. That’s something Ghandi had, yes?”

This sounds a bit of a stretch, but Hirschbiegel is on a roll and wants to stress that Diana is a film made out of respect. He adds: “She was straight and honest, and tried to do good. People got that.”

Diana was certainly associated with many good works, but it would be hard to regard her as a straight deal. Famously, she wasn’t above strategic manipulation of the press, when it came to beating Prince Charles in the PR War of the Waleses. But Hirschbiegel’s beguilement and my cynicism embody the polarised debate that is currently raging around his movie. According to the first-night reviews, the film is too soppily respectful of Diana. Based on a book by Kate Snell, and adapted by the Liverpool playwright Stuart Jeffries, it’s certainly more generous and less exploitative than Ken Loach’s Diana would have been, portraying the affair between the princess and the surgeon (Naveen Andrews), as two people caught between love and other loyalties, as if they were the stars of an ennobled Brief Encounter.

“That’s the ultimate aim,” says Hirschbiegel, eagerly, and then laughs. “But that was David Lean. I am Hirschbiegel. My attraction was that it is a universal love story and I hope it holds.”

He says he always knew what he was letting himself in for, and never blinked. Others did: Zero Dark Thirty’s Jessica Chastain was originally set to play Diana when it was still called Caught In Flight, but later pulled out, citing scheduling conflicts. Naomi Watts turned down the role twice; but in the end Hirschbiegel flew to New York in January 2012 and convinced her to don a prosthetic nose and take the part.

Watts is not a physical double for Diana – she’s half a head shorter, with a strong Australian accent – but camera angles, and voicework with Penny Dyer, Helen Mirren’s coach for The Queen, sought to blur those edges, along with a wig of honey blonde hair and eyes rimmed heavily in eyeliner.

Diana is the only royal portrayed in the film, except for a brief moment when Diana waves off her two young sons into a helicopter headed back to Prince Charles. There had been other scenes planned, including a sequence where Khan plays cricket with the princes. In the end, this was dropped because Hirschbiegel felt it was wrong for the film and partly because “as a father, I am concerned about the children”.

Still living in London, Dr Hasnat Khan was approached by the film-makers, but did not co-operate on the film, and last week criticised it for drawing on sources who could not have known the full story. Hirschbiegel’s defence boils down to artistic licence; “It is not a documentary, but a dramatic interpretation.” A dreamy music montage where the couple tour the white cliffs of Dover was one invention, but Hirschbiegel says the film needed a sequence “when you can see how much they enjoy each other”.

Ebullient and enthusiastic, despite weeks of globetrotting interviews stretching ahead of him, Hirschbiegel’s instinct is to shrug off any British media hostility. “They didn’t want to like it,” he says. “And if I’d come up with a more critical biopic, they would have hit at me just as well. It’s to be expected. And I don’t blame them – they own her, whether they are royalists or anti-royalists. We dared tell a story about her last two years that was a love story and very private and unknown.”

He’s probably right: this is not a film for the media, and the coverage virtually guarantees a strong opening for the film this month.

Nor is this the first time he has been presented with alternate readings of one of his films. After Downfall was nominated for best foreign film, the scene where a furious, defeated Hitler unleashes an impassioned, angry speech to his remaining staff received an unexpected second life as a subject for YouTube parodies on everything from the Scottish referendum to the break-up of the pop group Oasis.

Eventually YouTube and the studio decided enough was enough, and agreed to withdraw the spoofs, but a self-regarding filmmaker might still have found breath to rage about the misappropriation. Instead, Hirschbiegel admits he has watched almost 200 versions, and many made him laugh. “If I got royalties,” he quips. “I would have been even happier.”

• Diana is on general release from Friday