The supreme court has dismissed an emergency application to hear a right-to-die case challenging the legal ban on assisted dying.

In a three-page decision issued on Tuesday, the UK’s highest court turned down the request from lawyers for Noel Conway, a retired lecturer who is paralysed from the neck down by progressive motor neurone disease.

The three supreme court justices – the supreme court president, Lady Hale, the deputy president, Lord Reed, and Lord Kerr – acknowledged that the issue was of “transcendent public importance”.

But the justices decided there was little chance of success if Conway’s claim were heard in full by the court. “Not without some reluctance, it has been concluded that in this case those prospects are not sufficient to justify giving permission to appeal,” they said.

The judges stressed any change to the law would have to be for parliament, although it would be within the supreme court’s powers to make a declaration that UK law was incompatible with Conway’s rights under the European convention on human rights.

The three justices were not unanimous in their approach to such a complex issue, they noted.

“These are questions upon which the considered opinions of conscientious judges may legitimately differ. Indeed, they differ among the members of this panel,” the judges said.

They said Conway could bring about his own death by refusing consent to the continuation of the “non-invasive ventilation” keeping him alive.

Helping someone kill themselves is a criminal offence carrying a maximum sentence of 14 years in prison.

The government argued in a brief application hearing last week that modern palliative care allows some patients to die if they withdraw from artificial ventilation.

But Conway’s counsel, Lord Pannick QC, told the court such a death “could last only a few minutes, but in some cases hours, and other cases days”. It would induce a “drowning sensation” and would not constitute a dignified end, he added.

Responding to the ruling, Conway, 68, from Shropshire, said: “Today’s decision is extremely disappointing. It means that I will not be able to have my arguments heard by the highest court in the land. Dying people like me cannot wait years for another case to be heard.

“I am particularly disappointed that the courts have instead listened to the arguments of doctors who have never met me but think they know best about the end of my life.

“I have no choice over whether I die; my illness means I will die anyway. The only option I currently have is to remove my ventilator and effectively suffocate to death under sedation. To me this is not acceptable, and for many other dying people this choice is not available at all.

“All I want is the option to die peacefully, with dignity, on my own terms, and I know that the majority of the public are behind me. It is downright cruel to continue to deny me and other terminally ill people this right.

“This is the end of the road for my case, so we must now turn our attention back to parliament. I hope that MPs will listen to the vast majority of their constituents and give people like me a say over our deaths.”

Sarah Wootton, the chief executive of Dignity in Dying, said: “This decision is a grave injustice for dying people across the country who want to have a say in how and when they die.

“Not only does [it] let down dying people, it lets parliament off the hook. When more than 80% of the British public want to see a change in the law on assisted dying, and when countries such as the US, Canada and Australia can all craft compassionate, safe laws to allow their citizens this choice, we must ask why the UK is being left behind.”

Conway’s solicitor, Yogi Amin, of the law firm Irwin Mitchell, said: “Noel … has proposed a new legal framework for terminally ill people with robust safeguards. This would be in place of the current blanket ban on assisted dying.

“The world has changed phenomenally in the past few decades, with many medical advances, but the law on assisted dying for those who are terminally ill hasn’t changed for more than 50 years.”

Dr Peter Saunders, campaign director of Care Not Killing, welcomed the ruling saying: “The judges, parliamentarians, doctors and disability rights groups are all in agreement – that the safest law is the one we currently have. It carefully balances an individual’s rights with the need to protect vulnerable people, who could feel pressured into ending their lives. We have seen in the US states of Oregon and Washington that the fear of becoming a financial, or care burden is cited by more than half of those choosing to end their lives.

“And it is not just in US where we have seen disturbing developments, once safeguards have been removed. In Holland and Belgium, a law introduced to alleviative the suffering of mentally competent adults is routinely used on non-mentally competent adults and even children. This is why in this area the blanket ban is the right approach and we welcome the supreme court’s decision to reject this dangerous change.”