In an extraordinarily intimate and previously unpublished interview, which took place around the time he discovered he had cancer, Hughes revealed that feelings of guilt about the suicide of Plath, who gassed herself in their north London home in 1963, had never left him.
The Poet Laureate refused to speak about the death of his first wife, an American, for which he was constantly blamed by feminists, but in the last years of his life produced an astonishing volume of poems, The Birthday Letters, about the couple's relationship.
In the interview, with Eilat Negev in 1996, he spoke with regret of his attempts to avoid facing the sorrow he had suffered. "Today I think I should have written about it at least for myself and perhaps not shown it to anyone. At the time, I believed it better to leave it to nature to cope with the tragedy, to nature alone, without pen in hand. I kept things to myself to prevent others from scrabbling in my life."
He also questions his initial decision not to tell his two children Frieda and Nicky how their mother died.
"I didn't know what to tell them about the circumstances so I kept quiet. They grew up without knowing she committed suicide," he said.
"I don't know what was the right thing to do but after her death I wanted all of us to live as if we had started anew. It was a wish to flee from the shadow of her death. I think I made a mistake."
Remembering Plath's depression and isolation living in Britain with him, Hughes hints at years of silent self reproach. "Her life in England, in the cold, far from her friends, was not to her liking. Apart from the loneliness she was sensitive to a particular anti-depressant drug. I sometimes find myself thinking that if we had stayed in her country of birth she would not have committed suicide."
While Hughes says he has no theory to explain his wife's final destructive act, he talks of Plath's own peculiar emotional "wound', a kind of hidden injury that lies behind every writer's creative impulse.
"Every work of art stems from a wound in the soul of the artist," he said, while discussing Plath's compulsion to express her pain in her poetry and in her novel, The Bell Jar.
"All her creative work tells just one story: her Oedipal love for her father, her complex relationship with her mother, the attempt at suicide, the shock therapy."
The work may have eased Plath's distress temporarily, but it offered no cure. "If Sylvia had been able to free herself from that one wound that racked her, she might have changed, led a normal life, even perhaps felt healthy enough to stop writing."
Plath's suicide followed Hughes' decision to leave the marriage for another woman, Assia Wevill, with whom he had another child, Shura. In 1969 the couple separated, and in an awful repetition of tragedy, she killed not only herself but their young daughter too.
The deaths compounded the popular view of Hughes as brutal and dominating. At readings of his books some feminists demonstrated and even accused him of murder.
"Such things influence libraries and book shops that refused to stock my books and universities that chose to teach Sylvia's poetry but not mine. I know I am an undesirable person," he said. He added that he had resisted the temptation to defend himself. "From the beginning accusing fingers were pointed at me but I remained silent. I haven't written about it, because I didn't want people to think I was exploiting the tragedy as a topic for literature but the less I said, the more others began to invent."
Regardless of his discretion, Hughes was dogged, he said, by biographers and by threats to make films about his life. He described his deliberate destruction of several pages from Plath's diaries which he was afraid his children might read, and he also predicted ruefully that, one day, a missing volume of her diaries that he presumed to have been lost or stolen would turn up to haunt him.
Without directly addressing his feminist critics, Hughes said he had made time for Plath to write by babysitting during the mornings. He said that he had also suggested subjects for her to write about when she suffered a creative block.
"I would prepare lists of topics, like a high school writing exercise, and once she had written on the topics I suggested, other things found release, her novel The Bell Jar and many Ariel poems."
But Hughes' memories of his first and most famous relationship with the woman he admitted he still felt "close" to, were not entirely bleak. Far from jealous of each other's burgeoning literary careers, Hughes claimed the couple urged each other on. "When there are two of you the atmosphere is supportive. It's easier to concentrate on what you are doing because both of you do the same thing. It's like singing together in the dark."
Culture, page 3