One call from Ted Hughes's mistress led to literary tragedy

The anguished marriage between the poets Ted Hughes and Sylvia Plath was finally destroyed by a single phone call to their home from the future poet laureate's mistress, a close friend of the couple has revealed.

The call, in July 1963, by Assia Wevill, a strikingly beautiful copywriter who was then married to another poet, precipitated a chain of events that ended in the eventual suicides of both women.

Its significance has emerged in a new biography of Wevill - until now a little-studied figure in one of the 20th century's greatest literary tragedies - which has already attracted criticism from one of the couple's closest friends.

The biography by Yehuda Koren and Eilat Negev claims that Hughes was so dictatorial that he forced Wevill to sign a two-page typed "manifesto" setting out how she was to manage their house, look after the children and even when she had to get up from bed.

Elizabeth Sigmund, 78, who was then a trusted confidante of Plath and Hughes, said yesterday that the biography had overplayed Wevill's role as a hapless victim of Hughes's predatory behaviour. Plath fled to the cottage Ms Sigmund shared with her then husband David after Wevill's phone call.

Ms Sigmund, who was interviewed by the authors of the new book, recalls that Wevill was "strikingly beautiful, absolutely extraordinary. People keep talking about her green eyes but they were a wonderful grey, almost violet grey."

Although she remembers Wevill as a "dreadful snob" who was ruthless in her pursuit of Hughes, Ms Sigmund says she has sympathy for her. "No matter how awful Assia was in her behaviour, I feel desperately sorry for her because she must have been in agony," she said.

In July 1963, Wevill was then in the early stages of her torrid affair with Hughes, described in the biography A Lover of Unreason: the Life and Tragic Death of Assia Wevill. On the evening of 9 July, her call to Court Green was answered by Plath, so Wevill put on an ill-disguised male voice. Plath recognised her and later ripped out the phone cord from the wall.

Soon after fleeing to the Sigmunds' cottage, she threw Hughes out, and he retreated to London to join Wevill. Ms Sigmund says the new book wrongly claims that Hughes then "shuttled" between both women. "From everything I know, and Sylvia was visiting me a lot then, Sylvia never had Ted staying back in the house at all - that's wrong."

Although immensely critical of Hughes's conduct, which she said included him seeing at least two other women and his next wife while living with Wevill, Ms Sigmund believes Wevill misunderstood how deeply in love he remained with Plath.

Two days after Plath's suicide, on 10 February 1963, Wevill moved with him into the flat in London where the American poet had gassed herself, using the oven in the kitchen.

Ms Sigmund said Hughes was "semi-conscious" with grief. "I think he was absolutely heart-broken and horrified about Sylvia's death. He looked absolutely destroyed."

Six years later, Wevill too took her own life and that of her and Hughes's four-year-old daughter, Shura, by gassing them both. Wevill's friends said she was distraught after Hughes had refused to marry her and settle down.