Right-to-die campaigner Paul Lamb has said he is "absolutely gutted" by the Court of Appeal ruling against his challenge.
"I was hoping for a humane and dignified end," he said. "This judgment does not give me that."
Like the family of Tony Nicklinson, Mr Lamb pledged to continue to challenge the law despite the latest defeat.
"I will carry on the legal fight - this is not just about me but about many, many other people who are being denied the right to die a humane and dignified death just because the law is too scared to grapple with these issues," he said.
To which Tony Nicklinson's family responded:
Tony Nicklinson's family, have confirmed they will appeal the Court of Appeal's ruling against them, have also praised the judges' ruling in favour of one of the three right-to-die challenges.
Right-to-die campaigner Paul Lamb, who wants a doctor to help him die in a dignified way, was not present for the reading of the unsuccessful ruling at the Court of Appeal.
The ruling was made by the Lord Chief Justice Lord Judge, Master of the Rolls Lord Dyson and Lord Justice Elias in London.
The trio had heard argument that people who are too sick or disabled to end their "unbearable" lives without help are currently being condemned to "suffer in silence or make desperate attempts to kill themselves".
Mr Lamb, 57, from Leeds, had won the right to join the litigation to continue the battle started by Mr Nicklinson, who died at home last August, a week after he lost a High Court bid to end his life with a doctor's help.
The family of late locked-in syndrome sufferer Tony Nicklinson and paralysed road accident victim Paul Lamb have lost their right-to-die challenges at the Court of Appeal in London.
Three judges rejected the Nicklinson and Lamb cases, but in a majority ruling the court allowed an appeal by a locked-in syndrome sufferer known as "Martin".
He had sought clarification of Director of Public Prosecution guidance relating to the position of health professionals in assisted suicide cases.
The daughters of the late right-to-die campaigner Tony Nicklinson, who have maintained his Twitter account, have issued the following message ahead of the High Court's ruling on their right to pursue an appeal to make assisted suicide legal:
Leading judges are due to issue their rulings on three cases this morning in the latest round of a right-to-die legal battle started by the locked-in syndrome sufferer Tony Nicklinson. They are:
- The family of the late Mr Nicklinson's appeal to challenge the illegality of assisted suicide.
- Paralysed road accident victim Paul Lamb's bid to make right-to-die legal.
- A third man, a locked-in syndrome sufferer referred to as "Martin", who wants to be allowed a "dignified suicide".
The cases are unbearably tragic, but they cannot be the basis for changing a law that could affect millions.
Those are the words of the chief executive of disability charity Scope, written when the right-to-die cases from Paul Lamb and the family of Tony Nicklinson were put to the Court of Appeal in May.
Ahead of this morning's High court ruling, click here to read his argument against disabled people taking their own lives.