The question of whether assisted suicide should be legalised is back before the courts. The High Court this week is being invited to declare that the Suicide Act 1961, which prohibits assisted suicide, is incompatible with Article 8 of the European Convention on Human Rights (ECHR), which protects the right to respect for private life. Whatever the High Court eventually decides, its judgment will inevitably work its way on appeal up to the Supreme Court.

Our courts clearly have the power, under section 4 of the Human Rights Act 1998, to declare legislation incompatible with ECHR rights. Declaring the Suicide Act incompatible would not itself decriminalise assisted suicide, but would put political pressure on Parliament to change the law. If Parliament failed to act, it could be accused of contempt for rights or the rule of law.

These accusations would be absurd and Parliament should be willing to defy any declaration that the Suicide Act must be changed. It should be for Parliament itself to decide freely whether to decriminalise assisted suicide. Any attempt to use the courts to pressure Parliament to change the law risks politicising the courts and distorting parliamentary democracy.

The question for the High Court is whether banning assisted suicide is a proportionate limitation on the right to privacy of the person who wishes to commit suicide but who needs (or wants) the help of another in committing suicide. This is not a new question. It has already been raised before the European Court of Human Rights, which held that the UK’s legislation does not flout the ECHR.

One might ask why, if the Strasbourg Court thinks the Suicide Act is compatible with the ECHR, the question continues to be discussed in our own courts. The answer is that in 2014, in the tragic case of Tony Nicklinson, the Supreme Court decided that it was free to go beyond the Strasbourg Court’s case law and to use the Human Rights Act to impose additional restrictions on Parliament.

This was a very important, and very dangerous, decision, which has empowered British courts and means that legislation, regulations and otherwise lawful executive actions are now at risk of challenge, not only by reference to the Strasbourg Court’s often dubious jurisprudence, but also by reference to whatever the British courts choose to add to that body of law.

In Nicklinson, the Supreme Court did not declare the Suicide Act incompatible with the right to privacy. The Court split, with five judges willing in principle to make a declaration, and another four thinking this would be a constitutionally improper intervention. Of the five, only two were willing to make a declaration in that particular case – the other three thought more argument was needed, although two of the three clearly suggested that if Parliament did not do the decent thing and change the law then they would be likely to make a declaration in a later case.

This was a very curious (and complicated) judgment. Lord Neuberger, the President of the Court, was one of those willing in principle to make a declaration of incompatibility but who seemed to hope that Parliament would change the law itself, without a formal declaration proving necessary. He effectively sought to encourage legal change without actually making a declaration himself.

In September 2015, the House of Commons decisively rejected the Assisted Dying Bill, which would have legalised assisted suicide in some cases. Whatever one thinks about the question, the debate was far-reaching and impressive. MPs considered the case for changing the law and a large majority found it wanting, partly because they were not persuaded it was feasible to design a system that would protect vulnerable people from being encouraged (or coerced) to kill themselves.

Inevitably, campaigners for decriminalisation took up Lord Neuberger’s tacit invitation, and began proceedings seeking a declaration that the law must change. Quite rightly, MPs had not given much attention to the Supreme Court’s decision – they simply considered the bill on its merits – but in a related debate some members of the House of Lords seemed to imply that if the courts were ever to make a declaration then they should abandon their opposition to changing the law.

Parliament should not outsource its responsibilities in this way: it should decide for itself what the law should be by thinking about whether autonomy demands freedom to be assisted in suicide or whether the rights of the vulnerable, and the sanctity of life, require the status quo be maintained. So the stakes are high: if the courts issue a declaration in this case they will be intervening on one side of a political controversy in a way that threatens Parliament’s lawmaking freedom.

The argument in the High Court this week is likely to focus on whether it is possible to design a system that permits assisted suicide without endangering the vulnerable. This is not a sensible question for a court to be asked to decide. It is a question for legislators, as part of their wider reasoning about whether it would be good for assisted suicide to be legalised.

This continuing attempt to use the courts, with the encouragement of some (but certainly not all) judges, to usurp Parliament’s freedom to decide what the law should be is a constitutional travesty. It confirms the dangers of the Human Rights Act and the risks that British judges, as much as their European counterparts, can pose to the integrity of parliamentary democracy.