A terminally ill woman will today start a landmark court battle to force doctors to let her die.

Lawyers for Kelly Taylor, who has been given less than a year to live, will argue that the decision by her healthcare providers to deny her medication that could lead to her death is a breach of her human rights.

Mrs Taylor, 30, from Bristol, is frail and endures constant pain as a result of two conditions affecting her spine, and her heart and lungs. She wants doctors to vastly increase her morphine dose to sedate her into a coma-like state - although that amount of the drug could also kill her.

If she entered a coma her living will would come into force and doctors would be asked not to provide artificial food or hydration. But her GP, St Peter's hospice in Bristol and the United Bristol Healthcare NHS trust have refused to provide the treatment, saying it amounts to euthanasia.

At an initial hearing this morning at the high court in London, her legal team will cite the European Convention on Human Rights, which outlaws "inhuman or degrading treatment", to argue that she should not be refused steps that will end her life.

The lawyers will argue that doctors can lawfully administer large doses of painkillers in such cases, and that Mrs Taylor's living will should be respected once she loses consciousness.

Mrs Taylor said: "I have made the decision because enough is enough. I don't want to suffer any more. I'm not depressed - I've never been depressed. I am a happy person. But my illness is now at the point where I don't want to deal with it any more.

"My consultant has told me that he does not expect me to live for another year. In that time I will deteriorate and that deterioration will become quite undignified. I want to avoid that.

"I hope the court will come to the conclusion that the decision by my GP and hospice was unlawful and that I can be sedated to the point that I become unconscious. And secondary to that, that my living will should then come into effect so that I can die."

Mrs Taylor suffers from the heart and lung condition Eisenmenger's syndrome. She also has a spinal condition, Klippel-Feil syndrome. Her doctors have been unable to find a combination of drugs to relieve her pain, as she is allergic to many of those normally used to treat Eisenmenger's.

Her solicitor, Richard Stein, said: "We have advised our client that she is entitled to seek this treatment and that it is unlawful for doctors to deny it to her unless they also take steps to find a doctor willing to provide it for her."

Mrs Taylor today called for a change in the law so that people with terminal conditions can choose to end their lives. Last July, Mrs Taylor attempted to starve herself to death as an act of voluntary euthanasia.

After 19 days she was in so much pain she decided it was less dignified than her medical condition and began eating again.

She has also considered travelling to one of the Swiss clinics that offer terminally ill patients the ability to commit assisted suicide. But she rejected the idea because she wants to die at home.

Mrs Taylor said: "While I have respect for people who go over there, it really shouldn't be necessary. We should have a law over here."

The chief executive of the pressure group Dignity in Dying, Deborah Annetts, said: "Mrs Taylor is in an intolerable position. Her case highlights the impossible dilemma that the current law presents to patients with terminal illness, where pain relief and palliative care do not work to relieve their condition."