Conran says of her first husband, Habitat founder Sir Terence Conran: "He was a **** about money, and I cannot forgive him for hurting our sons. Divorce is painful and children don't like it, and sometimes the painful things should just be forgotten, but the pain stays and some of it can just burst out." She adds in the interests of literary complexity that her eight years with him were among the happiest and most satisfying of her life.In the case of Mr O'Sullivan, Conran is far more precise in her use of language and the contemporary resonances of the words she uses Take, for example, Mr O'Sullivan's job title He is said to be a "consultant engineer". During the next year he only applied for one other job, hence the use of the word `layabout'."The couple married in 1972 and were divorced a couple of years later. Conran recalls: "I came back from a visit to my mother in Canada to find a note on the mantelpiece from Kevin It said: `By the time you read this I will be in Moscow. She justifies her use of language with some linguistic precision: "As soon as we got back from honeymoon he chucked in his job. "I wrote back on a postcard and told her that I was not going to be intimidated by her threats," she told a newspaper.

"She is obviously more interested in my ex-husband than I am and I wish her good luck with him. She'll need it."A belated shift towards irony in those last few words, but slightly spoilt by Conran referring to Glendinning with some relish in her interview as "the Hon Victoria G". This fails as a quip because it is precisely what, Glendinning, the daughter of Lord Seebohm, is.As for Kevin O'Sullivan, the mysterious character on whom the exchange of letters revolves, there is - as in all well drawn characters in literature - room for disagreement on his motivation and growth Conran claims the marriage left her in a "financial mess". Perhaps its subtext is a lesson to all biographers that intense study of your subject does not necessarily endow you with genius.

But Glendinning defends her style: "It was like being a schoolgirl writing a mischievous letter."Glendinning went on: "This is the second time to my knowledge - there may have been more - that you have libelled him Just how flaky can you get?"Superwoman was not impressed. She too was spurred to take up her pen, but deemed Glendinning unworthy of a letter. Instead, she told Conran that she was guilty of libel and blurted: "If you do it again there will be hell to pay from me, so look out."Fans of Glendinning's biographies will find this riposte decidedly disappointing If there is satire it is brilliantly disguised. What withering metaphor would she use to humiliate her erstwhile rival?Glendinning could have summoned all the political barbs, the satirical sweep of Swift, flavoured with the poise and style of Sackville-West.