So, is Keira Knightley any good anyway?

Julie Christie may pip her to the best actress award at tonight's Baftas, and some were gleeful when she missed out on an Oscar nomination...

Keira Knightley will tonight join a flock of Britain's premier actors at the Royal Opera House in Covent Garden, London – waiting and hoping to clutch a Bafta award, to add to the accolades of her short and charmed career.

At just 22, the star of Atonement – for which she is a contender for best actress – has already been nominated for an Oscar, twice for a Golden Globe, graced numerous magazine covers, is the face of Chanel and has starred in blockbusters such as Pirates of the Caribbean as well as period dramas including Dr Zhivago.

While critics believe she may be destined for greatness, however, few have her capacity to generate anger, antipathy and questions about whether she is genuinely good at her craft or just a slender clothes horse with a modicum of talent.

Blogs, gossip columns and celebrity websites groan under the weight of an anti-Keira backlash. According to the fashionable New York magazine Radar, "the lantern-jawed Brit couldn't act her way out of a paper corset".

The whispering over her weight was only ended when she successfully sued the Daily Mail after it implied she was anorexic last year.

When she failed to make this year's Oscar shortlist, headlines crowed that she had been "snubbed", "overlooked" and upstaged by her young Atonement co-star, Saoirse Ronan, 13, who was nominated.

Even when Knightley was in line for an Oscar for Pride & Prejudice in 2006, critics complained that she was too beautiful to play Elizabeth Bennet – Jane Austen's practical, clever heroine.

The criticism is unfair, say film experts such as Nick James, the editor of the British Film Institute's Sight & Sound magazine, who argued that Knightley is shaping up to become one of the great British actresses, even if she is not there yet. "There's a quite entrenched anti-Knightley camp which comes across quite a lot," he said. "I don't go along with that. It's because she's beautiful, very young and successful, and that incites envy. The Oscar nomination was perhaps too much but she was very good in Pride & Prejudice. She is very capable when she finds the right role and could be a great actress. Hollywood is always looking for young stars of that age group – Lauren Bacall was 19 in her first film. It's always been that way."

The veteran television film critic Barry Norman agreed. While believing Julie Christie is more deserving of the Bafta, he added: "Keira is extremely promising. She has it within her to be a huge star. I'd like to see her put a little more meat on, she is far too thin, but she has enormous talent. In Pirates of the Caribbean the only acting part went to Johnny Depp. Keira was just supposed to be decoration. The problem is we don't like young people being successful in this country."

The writer and commentator Kathy Lette, author of How to Kill Your Husband, also puts the Knightley phenomenon down to jealousy, and a little 21st-century sexism. "I think it's a case of 'women, beware of women'," she said. "Keira has committed the cardinal sin of being too thin. Male actors never have to endure this kind of media scrutiny about their appearance. Why can't we just concentrate on her astounding talent? The very reason [she] has such a strong screen presence is that she remains slightly enigmatic. Male journalists, too, should concentrate on her acting rather than her exterior decorating."

Knightley herself has condemned the media's obsession with her looks. "I think a lot of actresses go through this thing of living with gossip and being criticised for the way they look.

"It's sick the kind of pressure put on young women in the entertainment industry."