Proponents of assisted suicide believe support for legalisation is growing among lawmakers and the public around the world. In the past year three names have been added to the list of places which permit it. The BBC's Vincent Dowd investigates whether assisted suicide is set to become even more common.
Some say "assisted suicide". Others call it "assisted dying". Each term - and alternatives such as "mercy killing" and "death with dignity" - tends to reflect the differing assumptions which people bring to this intense debate.
Britain is by no means the only place where this debate is current. One obvious reason is that in the West more people are living into their 80s and 90s. Old people (and their families) are the most likely to face difficult choices about quality of life versus sheer survival.
SWISS 'SUICIDE TOURISM'
BBC News, Geneva
Concerns have been raised in Switzerland about so-called "suicide tourism", cases in which primarily British or German patients come to die.
The Swiss Academy for Medical Sciences believes the process happens too quickly, and wants regulations requiring a patient to have repeated discussions with his or her doctor over an extended period. This would appear to rule out the current practice of Dignitas, in which patients from outside Switzerland arrive, see a doctor, and die all in the same day.
The Swiss government has drafted two papers aimed at regulating assisted suicide, one suggesting restrictions to the current law, and another proposing a ban on assisted suicide organisations. The latter is highly unlikely to find support. The proposed restrictions are believed to include a requirement that the decision over assisted suicide must take place over an extended period, during which time the patient must be in Switzerland.
The proposals will go before the Swiss parliament, and it will be months, possibly years, before any change to the law takes effect. Members of the Swiss Academy who have been advising the government believe it is highly likely that laws preventing or at least strictly regulating "suicide tourism" will be adopted.
The existence of the much-publicised Dignitas clinic near Zurich means it is Switzerland which is often associated around the world with assisted suicide. Yet it is the Dutch who have led the way.
In the Netherlands, doctor-assisted suicide was legalised in 2002. That change followed a couple of decades when assisted suicide was acknowledged to be getting more frequent but was unregulated.
Now about 2,300 people opt to die by assisted suicide in the Netherlands each year, out of a population of almost 17 million.
If someone in Holland approaches their doctor wishing to die there are stringent safeguards and a second doctor experienced in the field must be consulted.
The patient must be suffering unbearably and have no hope of recovery. Sometimes that judgement can be relatively clear-cut. Far more contentious would be the case of a clinically depressed patient who believed life was simply not worth living.
However, the Royal Dutch Medical Association (KNMG) says its members overwhelmingly favour the present system. They say few Dutch doctors exercise their right to opt out of such discussions.
By comparison, and though the Dignitas clinic in Switzerland provides few figures, it is believed that in the last 11 years more than 800 people have died there.
In the US, the issue remains one for the individual states, although there have been failed attempts to outlaw the practice at a federal level.
The first state to permit assisted suicide was Oregon in 1998. This followed a ballot initiative. It is thought that about 400 people there have taken advantage of the law.
After a long gap, Oregon was joined last year by neighbouring Washington, also after a ballot. The first actual cases were in March this year.
In theory, Montana became the third US state on the list in December 2008. But in Montana the position is very different. The change came not after a referendum and all the attendant debate, but because of a court ruling.
District Judge Dorothy McCarter ruled that, under the constitution of Montana, 76 year-old retired truck-driver Bob Baxter had the right to ask his physician to help him die. Mr Baxter died of leukaemia shortly after the ruling was issued.
Euthanasia: taking deliberate action, such as an injection, or withdrawing medical treatment to end a person's life
Assisted suicide: providing the means, e.g. medicine, to allow a patient to end their own life
The state of Montana has asked the state's Supreme Court to overturn that ruling.
The fact there seems to be a new momentum to the debate in the USA is not accidental - the organisation Compassion & Choices has been lobbying hard to make assisted suicide more acceptable to more Americans.
So far, it seems to be having some success. And whether or not Montana ultimately allows assisted suicide, Compassion & Choices have other states on their target list.