Moulin Rouge, le sequel?

No, Kidman is to bring on-screen life to Grace Kelly. But while she probably had Helen Mirren’s Oscar-winning turn as the Queen in mind, early reports suggest the film is heading the same way as last year’s Diana – down the pan.

So, another biopic?

Not quite. Monaco’s royal family says the film is based on “erroneous and dubious historical references”, adding: “This feature film cannot under any circumstances be classified as a biopic.”

Why so bad?

Kelly’s marriage to Prince Rainier III is one of the great love stories of the 20th century – and prime fodder for the silver screen. While Grace of Monaco has been given the prestigious honour of opening the Cannes Film Festival on Wednesday, those who’ve seen pre-screenings tell of a rambling story of obscure mid-century French politics and a tepid performance from Kidman. Meanwhile, Rainier, played by Tim Roth, is presented as cruel, overbearing and distant.

What else has the family said?

Last week Grace and Rainier’s son, Prince Albert II, and their daughters Princesses Caroline and Stephanie said: “The Princely Family does not in any way wish to be associated with this film… and regrets that its history has been misappropriated for purely commercial purposes.”

Kidman vs the kids.

In fact, she’s on their side. “It’s a child’s job to protect their parent,” she told the Daily Mail. “I get why the children are upset. I can’t say much other than that I have great respect and regard for their mother.”