Ted Hughes’s passionate sequence of poems documenting his life with Sylvia Plath has the qualities of a lasting classic, says Heather Neill.

It seems inappropriate, sacrilegious almost, to respond to Birthday Letters in ordinary limping prose. Read Ted Hughes’s testament to his life with Sylvia Plath for yourself. Enter the world of these poems and, unable to escape until the last, you will be both unbearably moved and dazzled by their mastery.

Hughes, poet for children, nature poet, Poet Laureate, has always been popular with syllabus-makers. But alongside admiration for his craft, some adult readers have taken a salacious interest in his relationship with his American wife Sylvia Plath, the mother of his two children.

She committed suicide on an icy London day in 1963, gassing herself while the children slept. Hughes had left her for another woman and Plath swiftly became a feminist icon, the victim of “murderer” Ted.

The vivid anger in Plath’s own poetry, her obsession with the overwhelming grip on her imagination of her German father, who had died when she was eight, gave her an immediacy that spoke especially to young women. After her death - and perhaps, for her, before that - “Daddy” and Hughes became synonymous, a fact acknowledged here in “A Picture of Otto”, addressed to him: Your ghost inseparable from my shadow As long as your daughter’s words can stir a candle.

She could hardly tell us apart in the end.

Your portrait here could be my son’s portrait In an earlier poem in this sequence, “Visit”, Hughes describes how, with a drunken student friend, he lobbed soil-clods at a Cambridge window - not Plath’s it later turned out - and, 10 years after her death, read in her journal of her joy when she heard about the incident. He ends with the lines: You are ten years dead. It is only a story.

Your story. My story.

Some of the excited newspaper coverage of the past two weeks has indeed treated this book as if it were a kind of soap opera, a “story”. There is a narrative element, certainly, from the setting of the stage before Sylvia enters, through their passionate meeting as students, marriage, homes, publications (there are many references to Plath’s work), the birth of children, parting and ultimate tragedy, but there is much more.

Hughes draws a detailed psychological picture of the mentally anguished Plath, shot through with passion, regret, anger and loss.

Their first meeting is erotic and violent. In “St Botolph’s” he describes leaving a party having kissed her, stolen her headscarf and been bitten in return so that he bears ... the swelling ring-moat of tooth-marks That was to brand my face for the next month.

The me beneath it for good.

Already there is a premonition of tragedy. Death is an insistent presence in these poems. But his love for her is palpable, an attraction not to be denied despite the destructiveness within it and despite the cultural differences which helped to doom their partnership. In “Error” he describes her in Devon: Listening for different gods, stripping off Your American royalty, garment by garment Birthday Letters - the idea in the title is to reaffirm Sylvia Plath’s life and work - is a revelation, both literally, in terms of content and in its artistry, but it is also essential Hughes.

Here is the absolute assurance in a variety of forms, the clear, unsentimental observation of nature (in “The 59th Bear” for instance), the vividness of the moment recollected and reassessed in the light of experience, the mixture of everyday and heightened language.

Hughes has scarcely talked of Plath publicly, but he did occasionally speak (or write in interview-correspondence) about his work, notably to The TES in 1995. Then he took pains to identify his method when writing for children, but concluded that their responses could be surprising: “If they can recognise and be excited by some vital piece of experience within a poem, very young children can swallow the most sophisticated verbal technique. They will accept plastic toys if that is all they’re given, but their true driving passion is to get possession of the codes of adult reality - of the real world.” With a little introductory help, Birthday Letters could convert the most reluctant teenage poetry student.

On another occasion, in 1996, while discussing Lorca’s Blood Wedding, which he had just translated for a London production, Hughes recommended Lorca’s essay about “duende” to me. According to this, while an angel gives the artist light and a muse form, duende is “of blood, of the most ancient culture, of spontaneous creation”.

There was, Hughes said, “a tremendous scream in the writing of Blood Wedding, yet an almost Japanese control”. Both descriptions could apply to Birthday Letters.

Hughes and Plath, separated yet forever together, throwing light on each other’s work, now have an extra dimension added to any study of their poems. In the end, when the immediacy of the story has faded, the poems in Birthday Letters will remain, a perfect combination of the physical and spiritual, of blood, tears and intellect, of life and death.