A paralysed road accident victim, suffering the locked-in syndrome, was denied the right to euthanasia by the British court on Monday.
The Court of Appeal dismissed a challenge by Paul Lamb and the family of Tony Nicklinson against an August 2012 ruling in the High Court that Nicklinson did not have the right to ask a doctor to end his life.
The three judges hearing the case said it was the role of parliament to legislate on such a subject. The law "relating to assisting suicide cannot be changed by judicial decision", they said in a written judgement.
Nicklinson's widow Jane vowed to appeal the ruling by the Supreme Court, the top court in England and Wales, saying that continuing the battle was "part of Tony's legacy".
Another locked-in syndrome sufferer, known only as "Martin", won his case for clearer prosecution guidance relating to health professionals who assist suicides.
He would need a professional health worker or carer to help him reach the Swiss assisted suicide clinic Dignitas, and had argued that current prosecution guidance left it unclear whether such a person would face prosecution.
Nicklinson, 58, died at his home in August 2012, a week after losing a lengthy legal battle for the right to die.
Paralysed from the neck down by a stroke while on a business trip to Athens in 2005, he had refused food and contracted pneumonia after saying he was "devastated" by the decision.
Locked-in syndrome had left him unable to speak or move due to total paralysis of the muscles, but he remained fully conscious and aware of his predicament, which he described as "pure torture".
Former builder and father of two Lamb, 57, who wants a doctor to help him to die in dignity, won the right to join the litigation started by Nicklinson.
Lamb said he was "absolutely gutted" by the decision, but would carry on with the fight.
"I was hoping for a humane and dignified end. This judgement does not give me that," Lamb said in a statement.
Care Not Killing, an anti-euthanasia campaign group, welcomed the decision.
"The judges acknowledged these are three tragic cases but agreed with our view that it is not acceptable to expect the state to sanction and condone murder," spokesman Andrew Fergusson said in a statement.
Assisted suicide is legal in Switzerland, The Netherlands, Belgium and Luxembourg as well as in the US states of Vermont, Oregon and Washington.