A severely disabled grandfather has launched a fresh legal bid calling for guidance to be issued over assisted suicide in Scotland.

Gordon Ross, 66, who suffers from several serious medical conditions, is concerned about the future legal position regarding anyone who helps him end his life.

Mr Ross fears that should a time come when he has "had enough", he will not be capable of ending his life without help and that anyone who does assist him may be charged with murder or culpable homicide.

He believes such discrimination, on account of his disability, is unfair.

Mr Ross, who lives in a Glasgow care home, wants Scotland's top prosecutor, the Lord Advocate, to issue "sufficiently clear guidance" clarifying whether any person helping him would be charged with an offence.

Guidelines have been published by the Director of Public Prosecutions (DPP) in England and Wales but they do not apply in Scotland.

Mr Ross brought his case for a judicial review to the Court of Session in Edinburgh in May seeking the Lord Advocate to set out guidance on what circumstances he would take into account in deciding whether to prosecute someone who helped another individual end their life.

A judge later dismissed the petition.

His appeal against the decision is now being heard by three judges at the same court.

Mr Ross's legal team had argued that the Lord Advocate's ''failure'' to produce guidelines is incompatible with the disabled man's rights under the European Convention on Human Rights (ECHR).

Lawyers for the Lord Advocate disputed the claims and said the policy was "crystal clear".

In a written judgment issued in September, Lord Doherty said: "The policy is consonant with the rule of law. The public know what his policy is, and there is no suggestion that it is being applied inconsistently."

Mr Ross suffers from conditions including Parkinson's disease and the loss of sensation in his arms and legs. He is unable to walk and cannot feed or dress himself, or attend to his personal needs.

The former television producer's poor health meant he was unable to attend court but speaking before the hearing, he said: "I am utterly undaunted by the judgment at the Court of Session in September, in which Lord Doherty decided not to compel the Lord Advocate to publish guidelines regarding assisting someone to take their own life.

"I remain convinced that I am being unfairly discriminated against on account of my disability, which is why I am appealing against that decision."

Supporters of his case held a demonstration in Edinburgh's Parliament Square before court proceedings got under way.

Sheila Duffy, from Friends At The End (Fate), said: "We believe the court in September made an error in allowing the current confusion which exists over assisting someone to end their life.

"Gordon has been very clear that he has no plans to end his life and is in no way suicidal. He is severely disabled and needs help with the simplest of tasks most of us take for granted.

"He is seeking clarification of Scots Law to learn if, should his circumstances deteriorate further, anyone who assisted him would face prosecution for helping him end his life.

"Gordon has the full support of his family and friends who, although they want him to live as long as possible, understand how life could become unbearable for him in the future."

Speaking earlier, his youngest son Jon Ross said: "The guidelines exist down south, but not up here, so at the moment someone in my father's condition or just like his condition couldn't end their own life if they wanted to, but you or I could. We are quite able, therefore we can do it, they can't.

"Essentially as far as he sees it that's discrimination, that saying someone who isn't able bodied can't do something that someone who is able bodied can."

He told BBC Radio Scotland's Good Morning Scotland programme: "He's not in a position just now where he would want to end his life but he would like to be able to make that decision if and when the time comes. But he's not in that place at the moment."

Mr Ross said the family are "very proud" of his father.

"He's using this situation that has happened to him to try to help people who are in situations like him and worse," he added.

In May, proposals to legalise assisted suicide in Scotland were rejected at Holyrood.

After a debate, MSPs voted by 36 to 82 against the general principals of the Assisted Suicide (Scotland) Bill.