Have you noticed how irritatingly tinkly Christmas carols have become this year? Supermarkets and railway stations are awash with maddeningly syncopated or just plain twee versions of what were once favourite tunes. Christmas “tradition” seems to come with built-in parody. But there are a few relics of the pre Toys ‘R’ Us era.

The pantomime has, with some honourable exceptions, turned into a showcase for minor sports and media celebrities, but other present-day descendents of the Yule-tide mummers are telling all kinds of tales. Many have literary origins - there is still too little genuinely new writing for family or primary school audiences - based on Dickens, Kipling, R L Stevenson or the Arabian Nights. A welcome development in the case of two London shows is the adaptation of familiar stories by well-known writers from other disciplines who have approached their task with unusual respect and admiration for the original.

Carol Ann Duffy, a prize-winning poet, has made Grimm “speakable” at the Young Vic and John Mortimer, novelist and playwright, has adapted A Christmas Carol for the Royal Shakespeare Company. Neither has come up with a conventional play.

Tim Supple, artistic director of the Young Vic, admires Duffy’s poetry. She, it turns out, is a life-long Grimm enthusiast - she even had a younger brother who was for years burdened with the name of the dimmest, youngest brother, Dummling, in the story of The Golden Goose.

Supple chose the tales and Duffy set to work on Hansel and Gretel, turning it into a play. “I changed it quite a bit, made it funny and the stepmother was more sympathetic.” But Supple wanted something else. “No-one could quite believe I didn’t want a writer to do a script.” He chose a poet deliberately, “a wordsmith rather than a dramatist who could define the quality of the story in elegant, precise, accurate language.”

Duffy started again, working mainly from two academic translations, the Manheim version and David Luke’s Penguin Classic, with the Puffin (based on an early 19th century translation) to hand. The aim was to capture the true spirit of the tales, to allow no hint of prettification or talking down. It wasn’t an easy task. “The hardest thing for a poet is to keep yourself out of it. ” Duffy went through her finished work, paring it down further, taking out images, capturing the clear, rhythmic, austere quality of oral storytelling. There is a certain irony in employing a poet to rediscover the simplicity of pre-literate forms, but Supple required the tales to be “alive for the mouth” in a way that a scholar’s prose rarely is. “I loved it”, Duffy says. “It was a good discipline. And, of course, it was lovely to spend my days re-reading the stories.”

The chosen ones are Hansel and Gretel, The Golden Goose, Ashputtel (a variant of the Cinderella story), A Riddling Tale, in the tradition of puzzle riddles, The Mouse, the Bird and the Sausage, Iron Hans, The Lady and the Lion and The Magic Table, the Golden Donkey and the Cudgel in the Sack. Duffy and Supple agree that the stories represent rites of passage, that they provide children with a means of dealing with their deepest fears.

The order of presentation follows the pattern of growing up. Hansel and Gretel - the tale of the children who are left in a wood to starve by their poor parents, are imprisoned by a cannibalistic witch in her sweetmeat house and who escape by outwitting and killing her - expresses a common fear of early childhood: abandonment. Duffy (an admirer of Bruno Bettelheim’s thesis in The Uses of Enchantment) says the witch represents the deepest, unspoken terrors.

The last story in the Young Vic’s sequence (apart from the humorous fable about greed, The Magic Table) is The Lady and the Lion. This is as sophisticated as the legend of Sir Gawain and the Green Knight and confronts nothing less than the disintegration of a marriage. It bears similarities to Beauty and the Beast, but the Lady and her husband the Lion, an enchanted prince who assumes human form at night, enjoy a loving relationship which she travels the world to restore when he is bewitched by a mysterious princess.

Among the intervening tales are The Golden Goose, Ashputtel (both, at least in part, about sibling rivalry) and Iron Hans, whose boy hero achieves manhood. He is punished for disobedience by acquiring golden hair which marks him out, but, with the help of the powerful Iron Hans, he comes to the king’s rescue in battle and is granted his daughter in marriage.

Feminists may balk at the handing out of princesses by way of reward and, indeed, the stories are politically incorrect by modern standards, with women falling into two main stereotypes: virginal, innocent and beautiful or ugly and wicked (the equivalent of the Ugly Sisters in Ashputtel are an exception, being wicked and graceful).

Duffy put all that to one side, realising that this was not the time to explain a stepmother’s bad behaviour in terms of unemployment and valium dependency. Hansel and Gretel’s stepmother must be accepted as simply wicked and the witch as evil. (She does admit, though, that she “turned the volume up a bit” when Gretel takes the initiative and disposes of the witch.) As Supple puts it,the stories are “so definite about our unspoken fears, they deal with matters not easily thrown into the issue basket.” In any case, Duffy says, children do not necessarily identify with the obvious character. “When I was a little girl I didn’t have to be the princess; sometimes I was the person who did the rescuing.”

Duffy delivered, as requested, pieces of continuous narrative, very close to the original. “When someone speaks, they speak in my version too.” Her contribution is perceptible enough, however, as in these extracts from Hansel and Gretel. “At the edge of a big forest there lived a poor woodcutter with his wife and his two children” becomes: “It was no more than once upon a time when a poor woodcutter lived in a small house at the edge of a huge, dark forest, ” or “At night he lay in bed worrying, and he tossed and turned and sighed ...” is transformed into “Night after hungry night, he lay in his bed next to his thin wife, and he worried so much that he tossed and he turned and he sighed and he mumbled and moaned and he just couldn’t sleep at all.”

The general is made particular, place defined and feelings amplified, but there are no fundamental changes. The inherent violence and cruelty are not softened. Ashputtel’s stepsisters, for instance, slice pieces from their feet and thrust them, bloody, into the too-small slipper. At the end of the story their eyes are pecked out, one by one, as punishment for their unkindness.

It is a world of tough moral rules, but Supple thinks children can cope with this kind of violence. “It’s very matter of fact. Essentially these are not horror stories. In Ashputtel the stepmother and sisters are figures of villainy. The violence done is appropriate. Children easily handle the violence in Hansel and Gretel; when the witch dies they are focused on Gretel. It is a purging.”

The stories typically involve repetition; most things happen in threes. Duffy found these motifs helpful; for Supple they present a difficulty. He has had to invent ways of introducing variety visually and in the tempo.

Played in the round, neither playlets nor storytelling in the Jackanory sense, the tales are presented in contrasting styles. The Golden Goose (in which a train of people become physically attached to Dummling and his goose and cause the sulky princess to laugh) is close to farce, with what Supple calls a “robust, boxing ring quality”, while Hansel and Gretel is “almost a social realist thriller”.

The narrative voice is always present, but there is only occasionally a single narrator. Several characters may speak the story, sometimes describing themselves or their plight in what have become integrated stage directions. Supple believes the stories to be so powerful that his task is merely to find the best dramatic means of expressing them as they are, with the help of music and lighting At the Barbican in London, Ian Judge, best known for directing opera, musicals and rumbustious productions of Shakespeare, is working in quite a different way. His Christmas Carol, newly adapted by John Mortimer, is magical and high-tech, complete with flying sequences and ghostly presences. But the ultimate aim is very much the same: to give the whole of the original as far as that is possible. Mortimer is so enthusiastic about Dickens’s prose, especially such passages as the description of the shops stocked for Christmas and the Fezziwigs’ ball, that he has divided the words in sections for the cast of 22 so that everyone contributes to the storytelling. People tend, he says, “to take the dialogue scenes and dramatise those, leaving out some of the best bits.”

It has become commonplace to recognise Dickens’s theatricality, but some of his most passionate passages are in his own voice. In the case of A Christmas Carol, Mortimer reveals the fierce denunciation of poverty beneath the jolly Christmas story of Scrooge’s redemption.

Written in 1843, when Dickens was 31, in what Mortimer describes as “his most philanthropic phase”, A Christmas Carol was published instead of a pamphlet to be entitled An Appeal to the People of England on behalf of the Poor Man’s Child. Scrooge is redeemed when his conscience is pricked by the suffering of individuals known to him, but also by the symbolic children, Ignorance and Want, found hiding in the skirts of the Ghost of Christmas Present.

This, the kernal of that abandoned pamphlet, is as important as any of the better remembered scenes from the novella - and so, this too is faithfully reproduced in the Barbican production. Ian Judge has conceived, with the designer, John Gunter, a constantly-moving swirl of London society out of which emerge the characters for this and all the scenes.

Not so much Bah! Humbug! as God bless us, every one!

Young Vic box office: 071 633 0133. Many day-time performances.

RSC at the Barbican box office: 071 638 8891 Information: 071 628 2295 * An installation based on Grimms’ Tales, Leaves among Thorns, is in place at the Royal Festival Hall. Visitors can walk through a changing forest, look out for hidden princes and golden hairs and listen to a story. Free, from 10am to 10.30pm until January 3. IOU Theatre will perform ” a short sharp magical feast” in the installation on December 28, 29, 30 and 31. Free. The Company of Storytellers, on December 13 only, at 7.30pm, will use images from the Brothers Grimm to weave new tales in the forest. Tel: 071-928 8800.