The case of a terminally ill former lecturer will come before the high court this week in the first substantial legal challenge to the UK’s ban on assisted dying.

Noel Conway, 67, from Shrewsbury, was diagnosed with motor neurone disease in November 2014. His condition is incurable and he is not expected to live beyond the next 12 months.

The high court hearing, involving three senior judges, is scheduled to last five days. Conway is supported by Dignity in Dying and other organisations campaigning to change the 1961 Suicide Act. Those who seek help to end their lives are currently forced to travel to a clinic in Switzerland.

Last week several hundred supporters staged a protest on a Thames river boat outside the Houses of Parliament. Afterwards Conway said: “In the past months I have been struck by the number of people who, like me, want the right to choose how we die. Today has shown the huge strength of feeling of people who want the right to a dignified death.”

Ahead of the hearing, Sarah Wootton, chief executive of Dignity in Dying, said: “The British public overwhelmingly support a change in the law to give terminally ill, mentally competent adults like Noel the choice of an assisted death. [The high court hearing] will consider detailed evidence and legal arguments about whether the current law breaches Noel’s human rights.”

Conway’s lawyers will ask the courts to declare that the blanket ban on assisted dying under the Suicide Act is contrary to the Human Rights Act. They will argue that as a terminally ill, mentally competent adult, his right to a private life – which includes the right to make decisions on the end of his life – is unnecessarily restricted by current laws.

The case has been brought against the Ministry of Justice. Conway is represented by the law firm Irwin Mitchell. The organisation Humanists UK, whose Conway is a member, has been given permission to intervene in the case. His aim is to bring about a change in the law that would legalise assisted dying for those who are terminally ill and are assessed as having six months or less to live.

Andrew Copson, chief executive of Humanists UK, said: “It is completely wrong that people who are of sound mind but terminally ill or incurably suffering are denied the choice to die with dignity. The deliberate extension of suffering as a matter of public policy is a stain on our humanity.

“The majority of the public want change but as long as parliament is unwilling to act, it is up to brave individuals such as Noel to fight for all our rights. We will always stand with such courageous and public-spirited champions.”

The last time a right to die case was considered in detail by the courts was in 2014 when the supreme court asked parliament to reconsider the issue. Parliament debated the subject but rejected making any changes to the law.

Rabbi Dr Jonathan Romain, chair of the interfaith clergy group in favour of assisted dying, said: “Noel Conway’s case is important not just for him, but for all those – including many people of faith – who believe that parliament needs to be given a clear signal by the courts to introduce legislation that permits terminally ill people of sound mind to opt for an assisted death if they so wish, rather than endure further suffering as they decline. It is not only their human right, but in keeping with religious ethics too. There is nothing sacred about suffering, nothing holy about agony.”

Earlier this year, Conway explained why he was fighting the case: “I am going to die, and I have come to terms with this fact. But what I do not accept is being denied the ability to decide the timing and manner of my death. I am not prepared to suffer right to the end, nor do I want to endure a long, drawn-out death in a haze of morphine.

“The only alternative is to spend thousands of pounds, travel hundreds of miles and risk incriminating my loved ones in asking them to accompany me to Dignitas [in Switzerland]. This would also force me to die earlier than I want.

“The option of an assisted death should be available to me, here in this country, in my final six months of life – this is what I am fighting for. It would bring immense peace of mind and allow me to live my life to the fullest, enjoying my final months with my loved ones until I decide the time is right for me to go.”

A separate legal challenge is being brought by a man identified only as “Omid T”, who is also a member of Humanists UK. He is suffering from an incurable condition which causes multiple systems atrophy. His case will be heard in the autumn.

• In the UK, the Samaritans can be contacted on 116 123. In the US, the National Suicide Prevention Hotline is 1-800-273-8255. In Australia, the crisis support service Lifeline is on 13 11 14. Hotlines in other countries can be found here.