The Divisional Court's judgment in the cases of Tony Nicklinson and 'Martin' is awash with statements that it is for parliament alone to legalise assisted dying. However, there is little appetite for statutory legalisation in Westminster. Meanwhile, Tony and Martin are condemned to live against their wishes.

Tony Nicklinson and Martin (whose identity is subject to an anonymity order) both suffer from locked-in syndrome, which renders them incapable of ending their lives without assistance. Both describe their lives as 'undignified and intolerable', and sought judicial review to clarify the law on assisted dying so that they may receive lawful assistance to die.

Martin's case was based on the fact that he would be physically capable of initiating the process that would lead to his death, but his wife is not willing to assist him to travel to Dignitas in Zurich. He sought an order requiring the Director of Public Prosecutions (DPP), Keir Starmer, to amend the Policy for Prosecutors in respect of Cases of Encouraging or Assisting Suicide, so that a person who was not a close personal relation would know on balance of probabilities whether they would be prosecuted for helping him travel to Switzerland to receive suicide assistance.

In addition, Martin sought a declaration (an order clarifying a point of law) on the likelihood that a doctor or solicitor providing suicide assistance would face professional disciplinary action from the General Medical Council or Solicitors Regulation Authority respectively. In the alternative, he sought a declaration that section 2 of the Suicide Act 1961, which criminalises encouraging or assisting suicide, was incompatible with his right to private life under article 8 of the European Convention on Human Rights (ECHR).

Although Tony Nicklinson would in principle be able to travel to Switzerland by virtue of his family's support, he could not receive suicide assistance there because his physical impairments would prevent him from participating in his own suicide to the necessary extent. Consequently, he sought a declaration that the common law (the body of law made by the Courts as opposed to Parliament) defence of necessity would be available to a charge of murder in a case of voluntary euthanasia (where a person kills another with his consent, and it is in his interests to die) provided by a doctor in England and Wales. He also sought declarations that section 2 of the Suicide Act 1961, as well as the legislation which sets out the mandatory life sentence for murder, were incompatible with his rights under article 8 of the ECHR.

The court rejected Tony Nicklinson and Martin's submissions on all grounds. In his concluding remarks, Lord Justice Toulson stated, 'it is not for the court to decide whether the law about assisted dying should be changed and, if so, what safeguards should be put in place. Under our system of government these are matters for Parliament to decide'. The Court based its decision on a wealth of authority, in particular the case of Tony Bland, in which the House of Lords ruled that it was not murder to withdraw or withhold artificial nutrition and hydration from a young man who had been left in a permanent vegetative state following the Hillsborough football disaster.

In Bland's case, Lord Goff stated:

"Euthanasia is not lawful at common law ... there are many responsible members of our society who believe that euthanasia should be made lawful; but that result could ... only be achieved by legislation which expresses the democratic will that so fundamental a change should be made in our law, and can, if enacted, ensure that such legalised killing can only be carried out subject to appropriate supervision and control."

Echoing these statements, Lord Justice Toulson offered three reasons for refusing to develop the law so as to allow necessity to operate as a defence to murder in cases of euthanasia. First, the Court did not have the power to consider an issue of such moral, medical and practical complexity. Second, it would be unconstitutional for the Court to usurp the role of Parliament in making profound change in an area of substantial disagreement. Third, only legislation would be able to create a legal regime for assisted dying with procedural safeguards and monitoring. Tony Nicklinson and Martin's other claims were rejected on similar grounds.

However, Parliament, in particular the elected House of Commons, has failed to grasp the assisted dying nettle.

In March 2012, the House of Commons debated the DPP's Policy on Assisted Suicide, which was issued following the House of Lords ruling in the case of Debbie Purdy in 2009. This was the MPs' first debate on assisted dying since 1999. While MPs welcomed the Policy, which effectively decriminalises assisting suicide for close personal relations acting on compassionate motives, they declined to support a consultation putting the policy on a statutory footing. In doing so, the Commons sent a clear message that assisted suicide, and more broadly assisted dying, is not Parliament's concern notwithstanding the apparent benefits of legal change on assisted suicide, and widespread public support for assisted dying in some form.

The reticence among MPs to engage meaningfully with the legalisation debate, barring the few notable exceptions who publicly favour or oppose assisted dying, may result not from moral or informed practical considerations, but a realisation that endorsement of assisted dying is a potential political deal breaker. Former MP Dr Evan Harris' support for voluntary euthanasia (and abortion) led to him being branded 'Dr Death', and provided a campaign platform for Christian Conservative Nicola Blackwood, who won from Harris the safe seat of Oxford West and Abingdon in the 2010 General Election.

Opposition to assisted dying emanates from a number of powerful interest groups, such as the Anglican and Catholic churches, pro-life groups, the disability rights lobby, and those who believe that palliative care is a panacea for all human suffering (which neither Martin nor Tony Nicklinson receive.)

These groups all advance a practical objection to assisted dying that must strike fear into the hearts of elected politicians: while assisted dying might benefit some people, such as Tony Nicklinson, Martin, Debbie Purdy and Dianne Pretty, it will lessen the protection afforded to 'vulnerable' members of society. Therefore, by active or passive pressure, the vulnerable will request assistance to die against their wishes or interests, and no legal regime can provide adequate safeguards against this. Since the vulnerable are described as 'faceless' and 'voiceless', there is no way of knowing how many there are in each constituency; thus to support assisted dying entails significant political risk. The vulnerability objection is therefore an effective way of keeping the appetite for debate over assisted dying low, and on the rare occasion that the debate surfaces, getting career politicians to leap to the opposition side of the fence.

The House of Lords has been more willing to confront assisted dying, having considered five bills on the subject since 1936, as well as a recent amendment to the Coroners and Justice Bill 2009 that would have legalised assisting a person to travel to a country where suicide assistance is lawful (such as Switzerland). However, the vulnerability objection has also come to dominate the debate among Peers. It was largely responsible for the defeat of Lord Joffe's Assisted Dying for the Terminally Ill Bill in 2006, along with parliamentary skulduggery on the part of the Bill's opponents. Thus even unelected Parliamentarians are sensitive to the accusation that they are exposing an apparently large class of people to the risk of abuse, or enshrining in law the statement that some people's lives are worth less than others.

That is not to say that politicians should not take the vulnerability objection seriously. However, it deserves careful scrutiny, and not blind acceptance. Opponents often claim that empirical evidence from jurisdictions where assisted dying is lawful, in particular the Netherlands, provides authority that safeguards, scrutiny, and control are impossible. However, such 'evidence' is often unsupported by actual data. While we should be cautious when interpreting the experience of other jurisdictions, since legal and social outlooks may be quite different to those in England and Wales, the evidence suggests that it is possible to institute safeguards around the practice of assisted dying. The correct moral and legal criteria for assisted dying, as well as appropriate before- and after-the-fact scrutiny may allow us to strike a balance between the plight of people like Tony Nicklinson and Martin, who at present are condemned to live, and protection for the vulnerable. However, so long as a vocal minority continue to raise the spectre of a society in which those who need love and care are pressured into ending their lives, and this assertion is not refuted by evidence-based scrutiny, it is unlikely that legal change on assisted dying will result from the political process.

With respect, the judiciary would do well to stop looking to Parliament for legal change on assisted dying, and consider whether they can effect it themselves.

Isra Black is a PhD candidate and visiting tutor at the Centre of Medical Law and Ethics, King's College London. His PhD project, entitled 'Better off dead? Best interests assisted dying', explores the possibility of a new model for legalisation of assisted suicide and euthanasia in England and Wales.

The views and opinions expressed are those of the author and do not necessarily reflect the views of King's College London.