It is inevitable that the motor neurone disease will be fatal, usually from respiratory failure brought on by wasting of muscles.
However, she will remain fully aware and able to think clearly even if she is unable to speak or move.
As they arrived at court, her husband Brian said: "Did it really have to come this far to allow her to do what she wants? It should never have come this far."
An hour into the hearing, Mrs Pretty had to leave the court because she felt unwell.
Doctors are, under current law, allowed to apply to the court for permission to withdraw feeding and hydration from patients who are in a "persistent vegetative state" and judged almost certain never to make any form of recovery.
However, an application of this type - relating to a conscious, and, as yet, not completely disabled patient, has never been made.
Mr Havers said there had been objections that a ruling in Mrs Pretty's favour would "open the floodgates" to others seeking similar undertakings from the DPP.
He said: "This truly is a rare or even a unique case.
"It is only going to be exceptional cases such as this that such an undertaking could be requested."
The Voluntary Euthanasia Society and civil rights group Liberty support Mrs Pretty.
Liberty had asked the DPP to guarantee her husband would not be prosecuted for aiding and abetting a suicide under Section 2 of the Suicide Act if he tried to help her.
But although DPP David Calvert-Smith conceded that Mrs Pretty and her family had to endure "terrible suffering", he said he could not offer such a guarantee.
The judicial review is expected to last for at least two days, and judgement is likely to be reserved until a later date.
I have found the Dianne Pretty case very interesting. My feelings about this case are quite strong. I think that the law should not have the power to let someone live in a horrible “vegetative state.” The woman should be able to have her own choice on whether she should be able to die. I feel that the government is choosing who dies and who doesn’t. Death should not be chosen by someone else. I am glad, however that there for was a lot of support for Dianne Pretty like from the “Voluntary Euthanasia Society”.
However, I also do feel that if they allowed Dianne Pretty to have an assisted suicide, it would encourage more people to use euthanasia for the wrong reasons. Many people could use this case as a chance for murder and killing. I feel that this is the only disadvantage for letting Dianne Pretty die. However, if Euthanasia was legalized nobody would have known about this case, therefore not encouraging anyone to kill.
Euthanasia ship to set sail for UK
Tuesday June 19, 2001
An Australian doctor plans to moor a floating euthanasia clinic off the coast of the UK administering lethal injections and drug dosages in a bid to raise the political profile of the mercy killing debate, SocietyGuardian.co.uk has learned.
Darwin-based Dr Philip Nitschke is travelling to the Netherlands this summer to buy a Dutch-registered ship so he can legally help end the lives of terminally ill patients around the world. He will meet with the activists who brought an abortion ship to Ireland last week to help set up the project.
Dr Rebecca Gomberts, the senior medic behind Women on Waves' abortion vessel, the Aurora, has already backed the voluntary euthanasia campaigner's plans.
"I've been very impressed by their impact," said Dr Nitschke. "I expect we could use a similar set-up for a euthanasia clinic, converting a small cargo vessel."
Dr Nitschke is investigating whether the Dutch parliament's recent decision to legalise euthanasia would enable him to circumvent the law in Australia, the UK and other countries where the practice remains illegal. Patients would be ferried to the ship where they would receive lethal injections or drug dosages.
"Many of my Australian patients are interested in the project. My legal advice suggests that a vessel operating in international waters will be subject to the laws of the land in which it is registered," he said.
Dr Nitschke, who rose to prominence when he helped four terminally ill patients to die after Australia's Northern Territory state briefly legalised euthanasia in 1996, intends to sail the clinic around the world.
"I would come to Britain, partially as a political statement given the legal situation over there [on euthanasia] despite the proximity to the Netherlands," he explained.
He is seeking financial backing for the ship and plans to discuss the cost implications with Women on Waves. "I'd expect it to cost at least $1m."
A spokesman for the Dutch health ministry claimed the project would be impossible under their new legislation, as the patients must have a long-standing relationship with the doctor and get a second opinion from another physician. "That would not be possible on a small ship," he suggested.
In the absence of his ship, Dr Nistchke's Australian patients intend to travel to the Netherlands to try to make use of the new euthanasia laws there. "The main focus of my trip this summer will be to try to make arrangements for my patients - meeting Dutch doctors willing to treat them," he said.
Australia's federal parliament overturned the Northern Territory's euthanasia law and the practice remains illegal throughout the country, but Dr Nitschke still runs "how-to-die" clinics and workshops in Australia and New Zealand.
"The clinics are for terminally ill patients - I've seen more than 200 on a one-to-one basis over the past three years," he said. "The workshops are for elderly but healthy people who want to ensure they die with dignity - many have seen relatives undergo a painful lingering death. They only began late last year but I've already seen more than 300 people."
Euthanasia is illegal in the UK - anyone helping another person to die could face life imprisonment. However, research by academics and the medical press has repeatedly found that between a third and half of doctors have given treatment to ease a patient's death.
Dr Nitschke's plans also look certain to re-ignite a recent dispute between two of Britain's royal medical colleges over a report on euthanasia.
The Royal College of General Practitioners refused to back a position statement on medical treatment at the end of life, drawn up by the Royal College of Physicians, arguing it failed to "break new ground".
The statement, published in the Journal of the Royal College of Physicians in April, says treatments that may shorten a patient's life can be accepted if the aim is to relieve suffering, but medical acts with the clear intention of ending a patient's life cannot be justified.
I think that having a boat travelling around the world is quite a good idea. However, I still think that it still has the same disadvantages. People would want to use it as a chance for murder.