Black Swan stars Natalie Portman as a ballerina hitting the big time. How realistic is the movie? We asked the cream of British ballet to give their verdicts

Black Swan, directed by Darren Aronofsky, claims to penetrate to the romantic, obsessional heart of ballet. Based loosely on Swan Lake, the film follows Nina, its ballerina heroine, as she grapples with learning the dual role of Odette and Odile (the white and black swans in Swan Lake).

Nina, played by Natalie Portman, is bullied by her mother and director, works herself punitively hard and becomes violently paranoid about her rival, Lily. What tips her over the edge is the challenge of dancing the Black Swan. As Nina tackles the sexy, malevolent role, she unleashes dark forces within herself that plunge us into full-on cinematic horror.

Prior to the film's US release last month, the dance community had imagined Black Swan to be an update of Powell and Pressburger's ballet classic The Red Shoes. As they've since discovered, the film has more in common with Roman Polanski's Rosemary's Baby: a terrifying portrayal of one woman's descent into madness, set in a world of claustrophobia and pain. Feathers have been ruffled: Robert Gottlieb, the New York Observer's dance critic, found Aronofsky guilty of "recapitulating all the old ugly misrepresentations of ballet", and of portraying ballet as one great "sadomasochistic trip".

Certainly, from the vomiting of guilty calories to the torments inflicted by her sadistic choreographer (with a foreign accent, of course), Aronofsky runs with every stereotype. And the dance sections are brutal: the deliberately choppy style of filming isn't just alienating; it also robs those moving bodies of their true power and beauty.

Portman has been widely praised: she spent months in training, allowing her to do some reasonable faking with her upper body, arms and head. Her main dance material, though, is performed by body doubles.

But what do real dancers think of Black Swan? In Britain, the film isn't out for another fortnight, so the Guardian invited five of the biggest names in British ballet to an advance screening. Were their screams those of recognition, terror – or sheer hilarity?

Tamara Rojo Principal dancer with the Royal Ballet

Natalie Portman needs to work on her port de bras. I really have a problem with this film using an actress, not a dancer, to play Nina: the director seems to think that, in a few months, you can learn a profession that it takes years just to understand, let alone be good at. And in the film, Nina is supposed to be awesome.

This is a very lazy movie, featuring every ballet cliche going. If you want to look at the dark side of ballet, do it properly, don't just give us shots of a ballerina suddenly vomiting. Nina's mother was beyond the cliche of a ballet mum – she was a psychopath. And the only people who looked like they were having a good time were the ones having sex.

The ballet movies that dancers go back to are the ones that have had great dancers in them, like Mikhail Baryshnikov, Moira Shearer, Roland Petit and Zizi Jeanmaire. Ballet isn't something you can just add on. The characters are important because they're dancers – and if they aren't very good ones, it doesn't make sense.

Lauren Cuthbertson Principal dancer with the Royal Ballet

I wish I wasn't a dancer looking at this film, so I could see it from another perspective. Portman is an incredible actress, and I can see why she jumped at this role. But, good as she is, it's impossible for her to look like a professional dancer. Maybe they needed her to sell the film, but [co-star] Vincent Cassel is a big name, too. And I'm sure they could have found a dancer of the right calibre to act the part.

Some of Nina's character felt accurate. We're all obsessive in how we approach a new role: it can dominate our thoughts for months. And some of us like to wear pastel colours sometimes. But in the film it's all so extreme. And Nina's such a good little girl; she wears pink all the time, and her hair in a bun, even when she's outside.

The film makes ballet look as though it's all blood, sweat, tears and sacrifice. Of course, that's suitable subject matter for a horror movie, but it doesn't show any of the pleasure.

Edward Watson Principal dancer with the Royal Ballet

The sad thing is that while this film shows the drive ballet dancers have to become perfect, it makes what we do look so naff and laughable. It doesn't show why ballet is so important to us – why we would want to try so hard.

The best part is the opening sequence, where you see Nina completely involved in her dancing. I didn't think Portman was bad: she had a good neck, face and focus. And the film was accurate about the stress levels in the profession. I've had those kind of dreams where I've missed performances, when I'm hearing the music, but I can't make it on to the stage in time.

But otherwise, it looked like they had taken all the cliches that they had been told about ballet and bundled them into a film. I've seen some choreographers play mindgames with dancers about who they are going to cast, but not with that kind of intensity.

The one cliche they didn't go for so much was the bitching. I thought there would be much more of it. I thought there would be dancers pushing each other down the stairs.

Elena Glurdjidze Principal dancer with English National Ballet

I was quite shocked by this; it wasn't at all what I expected. I thought Portman did quite well for someone who wasn't trained. She didn't look out of place at the barre, and I found it hard to tell when she was dancing and when it was the body double.

But so many scenes were exaggerated. And I didn't recognise anything about the ballet Swan Lake. When I was preparing for my first Odile [the Black Swan], I had a great dancer from the Mariinksy telling me that I had to be seductive like a cat, but it was all within the context of the choreography. Yes, you have to use you imagination to get into a role – but not like Nina. I must say, though, I did like the Black Swan eye makeup they gave her. She looked amazing.

Cassa Pancho Artistic director of Ballet Black

You can tell they did some research. Some of the smaller details, like the broken toenails and the way Nina works on her ballet shoes [scoring the soles, breaking down the blocked toes], were accurate. And I've seen dancers get paranoid, just like Nina, when they miss a rehearsal and find someone else has been standing in for them – although obviously not to the point where they smash the rival dancer in the mirror and drag her into the toilet by the ankles.

I hated the ballet director. He was ridiculously patronising and bullying. That scene when he comes into the class and starts telling the story of Swan Lake, then taps the shoulders of the dancers he doesn't want to use – if I tried that, my company would tackle me to the ground and send me to the hospital.

The most realistic character was Lily, who smokes and has fun. But even with her there are inaccurate details, like when she's rehearsing with her hair all loose. It's another cliche: "Look at me, I'm so relaxed because I don't put my hair into a bun."

Of course, this is a horror movie; it's meant to be extreme. There's been incredible feedback on Twitter, but what most people are saying is: don't worry about the ballet – go for the great lesbian action and the horror.

• Black Swan is released on January 21. Elena Glurdjidze dances Swan Lake at the Coliseum, London, in March; Tamara Rojo and Lauren Cuthbertson dance Swan Lake at Royal Opera House, London, March to April