We inhabit a world in which the answers to thorny moral questions are too often cast in black and white. Nuance is for losers: stray too far from your tribe and you’re accused of aligning yourself with rightwing religious fundamentalists or lefty woke warriors. Very little truly fits these social media-driven straitjackets. So it is in the case of assisted dying. As a liberal, assisted dying – enabling people with terminal illnesses to end their life at a time of their choosing – is something I feel instinctively in favour of. This sense is only piqued by testimony from people with conditions such as motor neurone disease who feel their life is no longer worth living, and who don’t want to pay thousands of pounds to go to Dignitas in Switzerland, or risk criminally implicating loved ones in assisted suicide. But stories now emerging from Canada, where medically assisted dying has been legal since 2016, have prompted me to think again. Canada legalised assisted dying for people suffering terminal illness six years ago, after a ruling by its supreme court. In 2021, this was expanded to voluntary euthanasia – medically assisted death for people not terminally ill, but with a “grievous and irremediable” medical condition. This was due to be extended to chronic mental illness from this March, although ministers have just announced they will delay this after concerns from doctors. Worrying stories have emerged that hint at a lack of safeguards: relatives shocked at doctors’ lack of probing of family members who have pursued voluntary euthanasia; the process being proactively suggested to veterans by government caseworkers, including Christine Gauthier, a former Paralympian who had been trying for five years to get the government to install a wheelchair ramp in her home and said it was “exhausting us to the point of no return”; a man with significant disabilities who testified to a parliamentary committee that nurses tried to coerce him into medically assisted dying by threatening forcibly to discharge him without the care he needed and denying him water and food for days. In the UK, assisting a suicide is a criminal offence. But the Crown Prosecution Service will only prosecute if it is in the public interest and prosecutions are rare – just 26 were proceeded with out of 174 referred cases between 2009 and 2022. Most proposals for reform that have been debated in parliament are for assisted dying – making it legal for doctors to help someone with a terminal illness who is likely to die within six months to end their lives – but some campaigners support the principle of voluntary euthanasia now enshrined in Canadian law. On the face of it, assisted dying might sound like a limited shift in the law that carries no risks of Britain ending up like Canada. But when you start probing its limits, it quickly becomes evident how difficult it is to draw a distinction between what is and isn’t permitted. There are no higher stakes than ending a life. How do you know someone is giving meaningful consent? The first plausible scenario that springs to mind is a coercively controlling abusive relationship in which a man puts pressure on his female partner diagnosed with end-stage cancer to end her life. Yet doctors are not particularly well placed to assess whether someone is being coerced. The latest parliamentary bill, introduced by Molly Meacher in 2021, contains the safeguard that a judge would need to sign off on assisted dying, but we also know from the family courts that judges can get coercive control very wrong. What evidentiary standard could there be to say there is no chance of someone’s life being wrongfully ended? The balance of probability, as in family law? Beyond reasonable doubt? There are other types of coercion, such as pressures from extended family. Disability rights campaigners point to the fact that even quite a mild suggestion from a relative or professional that it is something someone should consider could make someone vulnerable feel that it is the only right thing to do. In places where assisting dying is legal, studies suggest that not wanting to be a burden is a frequently cited reason. And how do we know how timeless consent may be? The perceptions of people with life-limiting – even terminal – conditions can shift quite significantly over time. What about the role depression might play in someone’s decision? Mental health diagnoses are not clear cut and there is some evidence that in Oregon, another jurisdiction where assisted dying is legal, a few who chose it may have had undiagnosed depression. The slippery slope – the idea that once you make any form of assisted dying possible it crosses a threshold that will inevitably become more permissive over time – has become a bit of a cliche, one that has been more true of some jurisdictions than others. But definitions are always malleable: in Canada, grievous and irremediable medical conditions include cases of people with severe chemical sensitivities opting for a medically assisted death because they have been unable to secure appropriate housing with the support of the state. “Terminal” can be less precise than it sounds: doctors say it is very difficult to accurately predict how long someone has left to live once you go beyond a few days. There lies another danger: we invest far too little in the palliative care needed to ensure that everyone has the most dignified and low-pain death possible. Huge improvements are possible and there remains significant discrimination against disabled people in the provision of health and personal care. Assisted dying could make improvements in this less, rather than more, likely. I have no doubt that there are some individuals who would benefit greatly from assisted dying and who ought to be granted the autonomy to choose this path. It is tempting to legislate with those individuals in mind, particularly given that end-of-life care in this country is not what it should be. But the more consideration I’ve given it, the more doubts I harbour that the risk of vulnerable individuals suffering a wrongful death as a product of abusive relationships or family pressure can be effectively eliminated. For now, that makes it difficult for me to support. Sonia Sodha is an Observer columnist