Kim Leadbeater has recently introduced a Private Member’s Bill in the House of Commons which seeks to legalise assisted suicide for the terminally ill. Despite its second reading being scheduled for 29 November, the text of the Bill is, somewhat remarkably given its significance, still to be published. Yet the outline of Leadbeater’s proposals has already become known. As such, I seek to offer here a legal analysis of some of the issues relating to legalising assisted suicide in the UK, and particular the idea that any law can be effectively limited to terminally ill adults.

For those who are opposed to assisted suicide, one of the main arguments against it is the inevitability of post-legislative expansion. Critics point to the way most assisted suicide laws have widened after enactment (if they did not start out being relatively broad, as in Switzerland). A recent letter to the Observer from a number of legal academics and practitioners (myself included) put it this way:

Canada has dropped its legal requirement that death be “reasonably foreseeable” and is set to allow euthanasia for mental illness in 2027. The Netherlands already allows euthanasia for the mentally ill and has proposed extending the law to elderly people with “completed lives”. Oregon has repealed its residency requirement and it is only a matter of time until its limitations to assisting suicide and to terminal illness—now being criticised as “barriers to access”—are dropped.

Those who support the Leadbeater Bill argue that there will be sufficient safeguards in it to prevent the UK sliding down a similarly slippery slope. On its face the Bill is limited to terminally ill adults with less than six months to live. The name of the Bill—“Terminally Ill Adults (End of Life) Bill”—has been chosen deliberately to prevent expansion by amendment when it is debated in Parliament. Parliament, the Bill’s supporters remind us, is sovereign, and no expansion of the law could ever happen without Parliament’s express approval. While such a defence is (on the whole) true in its basics, it only tells a partial story. For reasons I will now seek to explain, I don’t believe the Bill’s likely safeguards can be anywhere near as watertight as is promised. As such, there can be no guarantees that any assisted suicide law passed by Parliament will not expand in the future. The slippery slope is a legal reality, not a fiction invented by the Bill’s opponents.

My argument rests principally on the European Convention on Human Rights (ECHR). Assisted suicide engages several Convention rights, most obviously article 8’s “right to respect for … private and family life” but also the right to life in article 2 and article 3’s prohibition on “torture [and] inhuman or degrading treatment or punishment”. The relationship between assisted suicide and the ECHR has been set out recently by Stevie Martin in a detailed study, Assisted Suicide and the European Convention on Human Rights (Routledge, 2021). Martin and I disagree on the political question of whether assisted suicide is desirable, and I don’t agree with every argument put forward in her book. But Martin clearly has great expertise in this area, and her book is informative of how any British assisted suicide law might be interpreted by both the European Court of Human Rights (“ECtHR”) and domestic courts under the Human Rights Act 1998.

Currently the UK has a blanket ban on assisted suicide (Suicide Act 1961, s 2). As well as the sanctity of life, one of the main justifications for this is that it’s the only effective way of protecting vulnerable people who might otherwise feel pressured to end their lives prematurely. Until recently it was argued by successive governments that it would be impossible to enact a more limited assisted suicide law that adequately protected vulnerable people. Thus, while a blanket ban might be accepted as a prima facie interference with article 8(1) ECHR, it can be justified as a necessary, proportionate interference “for the protection of health” and “for the protection of rights and freedoms of others”. These are legitimate aims for which proportionate interference with article 8(1) is permitted by article 8(2).  Although Lord Neuberger in the leading Supreme Court decision on assisted suicide, R (Nicklinson) v Ministry of Justice [2014] UKSC 38, said, at [85], that a blanket ban is “a somewhat indirect and blunt instrument”, he nonetheless recognised that it “will protect the weak and vulnerable” (emphasis added). As Martin says (at p 97):

Arguably a blanket ban (i.e. one which covers everyone) will, because of its breadth, be ‘rationally connected’ to the objective. Ostensibly, it prevents everyone, including those who are vulnerable, from being assisted to die by suicide and, as such, is ‘rationally connected’ to the objective of protecting vulnerable individuals.

Martin goes on to say (at p 99), that “[t]he sheer breadth of the blanket ban, and the corresponding scope of the people ‘caught’ by it, presents a fairly decisive reply to any contention that it is not rationally connected to the objective of protecting ‘vulnerable’ people.”

However, once a blanket ban is lifted and assisted suicide is permitted for certain groups and not others, the force of any argument that exclusions from the law are necessary for the protection of vulnerable people becomes inherently weakened. This was made clear in the evidence given by John Finnis to the House of Lords Select Committee on Assisted Dying for the Terminally Ill Bill in 2005. Finnis, discussing legislative proposals to depart from the existing law’s “bright line” against assisted suicide, said:

In the new situation, any attempt to draw the line is necessarily artificial. The principles on which any attempted line would be based undermine each other and subvert the attempt to hold a line. If autonomy is the principal or main concern, why is the lawful killing restricted to terminal illness and unbearable suffering? If suffering is the principle or concern, why is the lawful killing restricted to terminal illness? Why must the suffering be unbearable if there is real and persistent discomfort? If suffering is unbearable, why should one have to wait for 14 days? If suffering and terminal prognosis are the concern, why is relief restricted to those who are capable of asking for it? Each of those questions is … a reason for doubting the rationality of any proposed line alternative to the present principled lines …

This is especially clear once article 14 ECHR is factored into the equation. Article 14 prohibits discrimination between people on a wide range of grounds in the enjoyment of Convention rights. If Parliament enacts a law that allows certain groups to be assisted in ending their lives—a law which, in this sense, entitles certain people to greater enjoyment of their article 8(1) rights—then any exclusion of others from this law will fall for intense scrutiny under article 14.

This will be a particular issue for people with pronounced physical disabilities. Martin (at pp 112–114) suggests that permitting assisted suicide for people with terminal illness while proscribing active euthanasia for those who are terminally ill, wish to die, but are too physically disabled to end their own lives themselves (e.g. they cannot swallow or otherwise administer life-ending drugs) will be hard to justify on article 14 grounds. She suggests it is incompatible with articles 8 and 14, read together, to deny the same opportunity of end-of-life medical assistance to physically disabled people as is offered to physically able people. While the ECtHR has not yet ruled on the permissibility of any distinction between assisted suicide and euthanasia (Switzerland’s law, for example, has not been challenged on this basis), the broader point on the relevance of article 14 to any assisted suicide law still stands.

Once it is recognised that the suffering and alleged loss of dignity experienced by terminally ill adults justifies the legalisation of assisted suicide, refusing to extend this to people who are not terminally ill but who nonetheless experience acute suffering will require the clearest justification under article 14. It cannot be argued that the lives of such people are more worthy of protection than the terminally ill. Nor could it be argued, once the law has shown itself capable of identifying a clear group for whom assisted suicide can be permitted, that a wider law could not be drawn extending assisted suicide or euthanasia to others. The UK would need the clearest justification for terminally ill adults being able to end their lives but not those experiencing equal or greater suffering because of physical disability, acute mental illness, etc.

Permitting assisted suicide for some groups but not others is therefore likely to deprive the UK of its principal justifications for a ban on assisted suicide. But it also raises pronounced questions about how the margin of appreciation and, by extension, domestic law’s doctrine of deference (cf. R (Elan-Cane) v Secertary of State for the Home Department [2021] UKSC 56), might work in this context. Cases like Mortier v Belgium (no 78017/17) recognise that assisted suicide, while permissible under the ECHR, is an area where the margin of appreciation is traditionally wide. But this margin of appreciation has principally been articulated in the context of challenges to blanket bans on assisted suicide, or conversely to any decriminalisation of it. Once a ban is partially lifted in the limited circumstances envisaged by Leadbeater, and article 14 is much more clearly engaged, the width of the margin of appreciation is far less certain. A leading textbook on European human rights law is clear that differential treatment based on a person’s disability status or medical condition will receive the most anxious scrutiny from the ECtHR (Harris, O’Boyle, Bates and Buckley, Law of the European Convention on Human Rights, 4th edn (OUP, 2018), p 789). The UK Supreme Court has made similar observations in relation to physical disabilities (R (SC, CB and 8 children) v Secretary of State for Work and Pensions [2021] UKSC 26, [112] and [136]). It is for this reason that Martin among other human rights scholars doubts the possibility of limiting assisted suicide to some groups of suffering adults and not others once a blanket ban is lifted (see, e.g., pp 189–190). Nor is this an argument that only human rights lawyers are making. It has recently been advanced by palliative care doctor Katherine Sleeman and health services researcher Iain Chalmers in the BMJ.

While it is true that the Strasbourg court has not so far required a European country to extend its assisted suicide regime beyond its initial limits, none of the European countries with assisted suicide laws is as ostensibly restrictive as the Leadbeater Bill seems likely to be. Belgium and Luxembourg’s laws extend to anyone living with a “futile medical condition of constant and unbearable physical or mental suffering that cannot be alleviated”. The Dutch law is similarly available to anyone with incurable conditions causing unbearable suffering, extending to anyone over 12 years old. Spain entitles people with “serious and incurable” diseases that cause “unbearable suffering” to suicide assistance. Switzerland, the country from which Dignitas operates, has one of the world’s most liberal assisted suicide regimes. While the European Court appears content with blanket bans on assisted suicide (Pretty v United Kingdom (no 78017/17)), there have been few opportunities for testing the legality of a partial ban as narrow as the one we are likely to see in the Leadbeater Bill. For reasons given above, there are significant questions as to whether such a Bill could be justified on article 14 grounds.

Even if it is accepted, however, that the Leadbeater Bill is vulnerable to challenge under the ECHR, does this mean that expansion is inevitable in the UK? In terms reminiscent of the last government’s attitude to the prospect of the Strasbourg Court finding the Rwanda scheme for “illegal” migrants unlawful, some supporters of the Leadbeater Bill insist that parliamentary sovereignty means there could be no forced expansion of the law. As a matter of strict domestic law, this is true. But it fails to tell the whole story. Under the Human Rights Act, domestic courts are afforded significant powers to bring domestic law into line with the ECHR. Not only must courts take into account Strasbourg jurisprudence under section 2 and interpret Acts of Parliament “[s]o far as it is possible to do so” in a Convention-compliant manner under section 3, but they are given powers to issue a “declaration of incompatibility” (DOI) under section 4 when they find domestic law to be irredeemably incompatible with the ECHR.

DOIs do not affect the legal validity of any Act of Parliament. But they are nonetheless highly significant and can have real legal consequences. For a start, they indicate to the government that any challenge to the domestic law in the Strasbourg Court is likely to succeed: that, as a matter of international law, the United Kingdom is likely to face an obligation to amend the law. But DOIs also unlock extensive executive powers under section 10 which allow the government to amend the law to cure its compliance issues: powers which can also be used if the ECtHR finds UK law to breach the Convention. If the Supreme Court issued a DOI against the UK’s assisted suicide law—as a majority of the court countenanced doing in the Nicklinson judgment— the government could amend the law and extend it beyond its limits without requiring Parliament to pass a new Act of Parliament (although the government’s remedial order would be subject to approval by resolution of both Houses, in accordance with the process set out in Schedule 2).  Sliding down the slippery slope is perfectly possible as a matter of law.

Admittedly, given the ethical sensitivities of the issue, the government might require Parliament to pass new primary legislation. But it is highly unlikely that the government would invite Parliament to refuse to follow a DOI or ECtHR judgment. Not only would this be a significant reversal of the near-constant practice of UK governments to respect both domestic DOIs and Strasbourg judgments, not only would it be a willing flouting of international law, but it would run contrary to recent statements made by the Attorney General and the Lord Chancellor on the importance of the rule of law. It is inconceivable that any assisted suicide law found to breach article 14 ECHR would not be amended. Proponents of assisted suicide need to acknowledge these issues and tackle them directly, rather than hiding under reductionist accounts of parliamentary sovereignty and a view of the constitution that ignores the Human Rights Act, the ECHR, and the importance of international law.

In summary, while Strasbourg seems content to accept blanket bans on assisted suicide, any limited assisted suicide law that discriminates on grounds of disabilities, medical conditions, etc. is liable to attract the closest scrutiny under article 14. If a domestic court were to issue a DOI or if the ECtHR were to find the UK in breach of the ECHR on that basis, it is likely that the UK government would respond by widening, or asking Parliament to widen, the scope of the law. The slippery slope is not a fiction, invented by scaremongering opponents of assisted suicide. It is a real possibility baked into the present law. And those seeking a change in the law need to acknowledge this and address these arguments head-on.

Philip Murray is a College Assistant Professor in Law at Robinson College, Cambridge.

I am grateful to Guy Baldwin, Mark Elliott, Rajiv Shah and the editors of this blog for their helpful comments on earlier drafts. An earlier version of this text was amended to clarify an ambiguity over section 10 remedial orders; I’m grateful to David Natzler for his helpful comment. All errors are mine alone.

(Suggested citation: P. Murray, ‘Looking down the slippery slope: Can assisted suicide be restricted to the terminally ill?’, U.K. Const. L. Blog (30th October 2024) (available at https://ukconstitutionallaw.org/))

*Editors’ note – the original post was amended on 31 October 2024 to clarify the legal position concerning remedial orders under section 10 and Schedule 2 of the Human Rights Act 1998