Severely disabled man wants doctors to be allowed to ease his death in the UK, or help him travel to Switzerland to end his life

A 46-year-old-man who wants to die after a stroke that left him almost completely paralysed is bringing a groundbreaking legal action that could effectively lead to the legalisation of assisted suicide in the UK.

Martin, as he has agreed to be called to preserve his anonymity and that of his family, was a fit and active man who enjoyed rugby, cars and socialising with friends in the pub before suffering a brainstem stroke three years ago. Now requiring round-the-clock care, his mobility is limited to moving his eyes and small movements of his head. He communicates by staring at letters on a computer screen which the machine recognises and forms into words spoken by a digitised voice.

Martin has been asking to die since six months after the stroke but says he has no one willing to assist him and cannot on his own organise a trip to the Swiss clinic Dignitas, where he could end his life legally. His wife, who chooses to be known as Felicity, says she will be with him if he dies but will not help bring about his death.

Human rights lawyers at the firm Leigh Day in London have taken the first step in an action on Martin's behalf that, if successful, could have massive implications. One possibility is that the case could lead to a court ruling that Martin has the right to help not only from a paid professional to assist him get to Switzerland, but also to the services of a palliative care doctor in the UK to ease his death, should he decide to end his life by refusing food and drink.

Such a ruling would dramatically alter the current options for seriously ill and severely disabled people who wish to end their own lives in the UK. "There would be no more planes to Switzerland," said Richard Stein of Leigh Day. "Why would you bother?"

However, Stein added that beginning this legal action would potentially put the lawyers working on it in legal difficulty, since both they and any doctor or psychiatrist who came to examine Martin for the case could be considered to be assisting his suicide, thus exposing them to potential prosecution or disciplinary action from professional bodies.

The case of Debbie Purdy in 2009 established that friends and family could help someone who is terminally ill travel to Dignitas with very little likelihood of prosecution on their return. Purdy has multiple sclerosis and wanted assurances that her husband, musician Omar Puente, could take her to Switzerland when she was ready to die, without legal consequences. In the guidance issued with the judgement Keir Starmer, the director of public prosecutions (DPP), made clear that those without a close emotional commitment who assisted a suicide – including professionals – could face criminal proceedings.

Stein is seeking an interim declaration from the courts that lawyers and doctors will not be prosecuted or disciplined if they prepare Martin's case. Even though many lawyers have worked on right-to-die cases before, neither the DPP, Solicitors Regulation Authority or the General Medical Council would give assurances that preparing the case was legally and professionally acceptable.

"The important thing is that lawyers and doctors will know that, providing they have assisted somebody to end their lives compassionately and in good faith, they won't face criminal prosecution or disciplinary action that will affect their livelihoods," Stein said.

If the interim declaration is granted Stein can take the next step on Martin's behalf – asking the courts to rule that a doctor should be able to assist him with pain relief and palliative care if he decides he wants to stop eating and drinking in order to end his life.

• This article was amended on 2 September 2011 to make clear that friends and family members who help someone who is terminally ill travel to Dignitas face very little likelihood of prosecution on their return.