The broken promises allegedly made to Natallie Evans were laid bare before the High Court yesterday as she fought for her "last chance'' to have a baby.

Miss Evans, 31, and Lorraine Hadley, 38, were beginning a landmark case to save their frozen embryos from being destroyed on the instruction of their former partners.

With her former fiancé Howard Johnston sitting a few feet away, she described how the couple had wanted to start a family. She said Mr Johnston had promised they would have a baby together using the embryos they had frozen before her pre-cancerous ovaries were removed. Months later they separated and he withdrew his consent for the embryos to be used.

Miss Evans and Mrs Hadley are challenging a man's right to "veto'' the use of an embryo made from his sperm.

Their solicitor, Muiris Lyons, said yesterday: "This case raises important legal, moral and ethical issues as to the right of an embryo, its status and position in law, and the competing interests of a woman desperate to become a mother and a man who has no wish to become a father."

Miss Evans said yesterday: "I want to use my embryo. It is my last chance to have a child of my own. I would do anything to have one.''

Miss Evans, who had wanted children since the age of 20, met Mr Johnston, a fellow employee at Virgin Mobile and five years her junior, in 1999. They moved in together, became engaged the following year and having decided to start a family sought advice from the Bath Assisted Conception Clinic. An oncologist told her that her ovaries had a pre-cancerous condition and needed to be removed.

She was taken to a meeting to decide whether she wanted to freeze some embryos for IVF treatment before removal of the ovaries. "Someone was trying to save my life in one office and in another someone was trying to help me have the child I desperately wanted - two different things so important to me,'' said Miss Evans, from Trowbridge, Wiltshire.

Together the couple opted to take up the clinic's offer, though Miss Evans insisted that she had considered alternatives, wary of the consequences should her relationship fail.

"Howard told me not to be a negative person. I was being silly. We were going to have a family together and we would get married and he was not going to leave me and I put my trust in him,'' she said.

Six months later, in May last year, the couple separated and he went on to withdraw his consent. Yesterday Robin Tolson QC explained that the six embryos - frozen in storage for up to 10 years - would give Miss Evans a 28 per cent "last chance'' of having a genetically related child.

Mrs Hadley's case, he said, was different. While she already has an 18-year-old daughter and had previously "vacillated as to whether she wants to go through the thrills and spills of motherhood again'' she nevertheless decided she wanted another baby.

Both men involved, after their relationships broke down, decided they did not want to father children, bearing in mind the emotional as well as financial implications.

The hearing is scheduled to last for six days. The two women's legal team will challenge the law, governed by the Human Fertilisation and Embryology Act 1990, which insists that the consent of both parties is required and can be withdrawn at any time before the embryos are used.