What could help

Tilted bed to help patient sit upright Spinal jacket to support the back Mechanical arms controlled by eye or mouth movements Keyboards activated in that way, allowing a patient to type A powered wheelchair offering independence Source: Mr Alan Gardner, of the charity BackCare

The woman's lawyer Richard Stein has told the BBC that his client is in full possession of her mental faculties, and is competent to make a decision to have the ventilator switched off.

Her doctors, who also cannot be identified, say their ethical training would not allow them to switch off the ventilator.

And they say she cannot make a truly informed decision before she has tried a rehabilitation centre, where she would be given special aids to try to improve the quality of her life.

Video link

The three-day hearing will begin at the hospital on Wednesday morning and return to the High Court in the afternoon, with the claimant able to watch proceedings on a video link.

Time is one of the important factors in patients making decisions

Vivienne Nathanson BMA

Mr Stein told BBC Radio 4's Today programme that someone who was well would find it difficult to understand what it felt like to be told you were likely to paralysed for the rest of your life.

He said: "She has been wanting to terminate that treatment ever since she has known the prognosis is so poor.

"Doctors seem to be, in a way over almost a year, imposing their wishes on her."

Mr Stein said his client would have to demonstrate to a judge that she is able to fully understand all aspects of her situation and arrive at a rational decision.

Vivienne Nathanson, head of science and ethics at the British Medical Association, said competent adults had an absolute right to make medical decisions.

But the question arose about who was competent to make those decisions.

She said doctors reluctantly resorted to the courts and knew from experience that patients can change their mind.

"Time is one of the important factors in patients making decisions."

But she said in cases involving children, doctors had to look beyond the wishes of parents and act in the best interests in the child.

Legal first

BBC legal affairs correspondent Jon Silverman said the case is unprecedented, because the woman is neither unconscious, nor deteriorating.

The High Court occasionally allows doctors to stop supporting lives of people in a "persistent vegetative state" with no chance of recovery or quality of life.

A so-called PVS patient is unconscious, but can continue living indefinitely if fed and hydrated through a tube. Their families are usually the parties asking for life-support to be ended.

The case follows the battle of Diana Pretty

In Wednesday's case, lawyers are citing the Human Rights Act, which bans "inhuman and degrading" treatment and bestows the right to respect for private life.

This case differs from the high-profile fight of Diana Pretty for her husband to be allowed to help her end her life, because that would require active steps to kill her.

A ventilator counts as medical treatment, which a patient who is capable of taking decisions may legally refuse.

This case is expected to set a new legal test of a person's competence to decide whether they wish to continue to have hospital treatment.