The issue has come to the fore again amid campaigning by Dame Esther Rantzen and while some countries already have assisted dying legislation, the issue is deeply divisive with strong opinions on both sides.
Details have been revealed of a planned assisted dying law that supporters say would offer the toughest safeguards in the world.
It could mean people in the UK with terminal illnesses can end their lives “on their own terms”, according to Kim Leadbeater, the MP behind the bill.
The list of proposed safeguards includes a life expectancy of six months or less, the ability for the patient to take the fatal drugs on their own, and the sign-off of two doctors and a judge.
However, some are still firmly against changing the law and believe it’s a step too far.
Why is assisted dying controversial?
A key concern is the so-called “slippery slope” argument.
Opponents argue a law might initially have strict criteria (for example, restricting it to terminal illness and excluding mental health conditions), but that over time these could be eased.
MP Kim Leadbeater said this hadn’t happened in countries that have brought in assisted dying laws.
“Where there are countries where the law is broader, that was always how it started,” she told Sky News last month.
“So I think there is a perception around the slippery slope concept, which actually isn’t reality.”
But there is one example of this: Canada has changed its laws.
It no longer requires the presence of a terminal illness – only a chronic physical condition. It had also been due to expand the laws to mentally-ill people this March, but the move has been delayed until 2027.
Other frequently-cited worries are that people could be pressured to end their life – perhaps by a relative who would benefit financially; that people might act because they don’t want to “burden” others; or that they could make an irrational decision while depressed.
Some opponents also say it’s against their religion or unethical for doctors and that the focus should be on improving palliative care to ease suffering.
However, those who support a law change, such as Dignity in Dying, insist “everybody has the right to a good death” – rather than suffering for months or years with a very poor quality of life.
The group says it should be an option for terminally-ill adults who are mentally competent.
It claims more than eight in 10 people favour changing the law and that currently some people are forced to choose “a lonely and perhaps violent death”.
Where else is assisted dying legal?
Among places to have a form of assisted dying law is Switzerland, where it’s been legal since 1942 to help someone to die as long as the motive is not “selfish”.
The country’s Dignitas group has become well-known as it allows non-Swiss people to use its clinics.
New Zealand brought in a law for terminally-ill people with fewer than six months to live following a 2020 referendum.
Every state in Australia also has some kind of assisted dying law. Victoria was the first to pass such legislation in 2017.
The Australian laws allow a person to self-administer life-ending drugs, or get a doctor to do it if they aren’t physically able.