It's traditional for Cannes to start with something spectacular. This is certainly no exception. It is a film so awe-inspiringly wooden that it is basically a fire-risk. The cringe-factor is ionospherically high. A fleet of ambulances may have to be stationed outside the Palais to take tuxed audiences to hospital afterwards to have their toes uncurled under general anaesthetic.

Grace of Monaco is a stately and swooning homage to Princess Grace, formerly Grace Kelly, focusing on her alleged courage in keeping plucky little Monaco safe for tax-avoiding billionaires. This was during its supremely parochial and uninteresting 1962 face-off with Charles De Gaulle, who wanted to absorb the principality and its monies into France's national bosom. So can Grace, by finally sacrificing her movie career on the altar of this cockamamie Ruritanian state, and flaunting her martyred couture loveliness, win the respect of the Monégasque folk and even the grumpy old Général himself?

The resulting film about this fantastically boring crisis is like a 104-minute Chanel ad, only without the subtlety and depth. Princess Grace herself is played by Nicole Kidman, wafting around the Palace with dewy-eyed features and slightly parted lips which make her look like a grown-up Bambi after a couple of cocktails, suddenly remembering his mother's violent death in the forest.

It doesn't seem that long since we endured a horrendous biopic of Princess Diana, that other super-rich blonde pasionaria — played by Naomi Watts. As audiences reeled into the foyer after that, they comforted themselves with the thought that surely things couldn't get worse. Surely they wouldn't be forced to endure another badly acted, badly directed film about a wealthy and self-pitying royal?

How very wrong. I can now actually imagine a creepy science-fiction short story about someone going back to prehistoric days in a time machine, killing a tiny trilobite, and then coming to the present to find everything the same, only now it's Naomi Watts playing Grace and Nicole Kidman playing Diana.

The movie begins with a sketch of jowly and adorable old Alfred Hitchcock (Roger Ashton-Griffiths) coming to Monaco hoping to tempt Grace back to the movies, proffering a juicy leading role in his latest film, Marnie. Two recent dramas about Hitchcock's troubled life — one for cinema, a better one for TV — have in fact begun in approximately the same way, but then followed the troubled director back to the US. Here, we stay with Kidman's Grace, who is effectively confronted by a dilemma. Should she return to her selfish, shallow life in Hollywood or build a new shallow, selfish life in Monte Carlo?

Nicole Kidman as Grace Kelly in Grace of Monaco Photograph: Julien Panie/Warner Bros



And so the terrible mental turmoil begins. She pores over the script, late at night, in bed, with stylish reading glasses. During the day, she tries her darnedest to impress the wittering ladies of Monaco by entering into the spirit of charity galas and such. She worries about plotting against her at court. She consults her confidant, one Father Francis Tucker, a sorrowing priest who is evidently permitted the familiarity of calling her "Gracie", played with conviction by Frank Langella.

Then, in order to bone up on the history and culture of Monaco — and perhaps because the situation is not yet sufficiently gay — Grace consults a local nobleman, Count Fernando D'Aillieres, played by Derek Jacobi. He scampers about the hillsides, with Grace in tow, filling her in on all the tiresome details, while also presuming to give her tips on acting and deportment. (Surely as an Oscar-winning star she knows this stuff already?) Jacobi has a little fun with the part, although it needed Ian McKellen to come on, playing the Count's ageing houseboy.

But how about the people for whom it is all supposed to be about? Her, erm, husband and children? Well, the absolute indifference shown by Grace to her kids here is startling. And what of Prince Rainier himself, that fairy-tale prince for whom she gave it all up? He is played by Tim Roth, who gives a very cigarette-smoking, glasses-wearing, moustache-having performance. He is always leaning in his chair, leaning against door frames — looking through his glasses, and smoking. What is this remarkable head of state thinking about? As performed by Tim Roth, it looks like he is thinking about how much he regrets taking this appalling role, and how inadequate he considers his fee, whatever it is.



An interesting, complex film could be made about a talented woman who decides to make the best of being trapped in an imperfect marriage. But such a film would have to stop curtsying, and really think about its subject.

• Five other dreadful films that premiered at the festival

• Right - so what else might be good at this year's festival? Here's 24 other contenders

• And here's a video on the beach at Cannes in which Peter and others discuss the programme

• Watch a video review of the film