Updated

A paralysed road accident victim and the family of a late locked-in syndrome sufferer lost their legal challenge at Britain's Court of Appeal on Wednesday for the right to die through assisted suicide.

Three judges at the court in London rejected the appeal brought by Paul Lamb, 57, and the family of Tony Nicklinson against a High Court judgment ruling Nicklinson did not have the right to ask a doctor to end his life.

Nicklinson's widow Jane has vowed to appeal the ruling at the Supreme Court, Britain's highest court, saying continuing the battle was "part of Tony's legacy".

The judges said the core reason for the decision was that it was the role of parliament, and not judges, to change the law on such a subject, saying the law "relating to assisting suicide cannot be changed by judicial decision".

In the judgment, Lord Chief Justice Lord Judge said parliament "represents the conscience of the nation" in life and death issues: "Judges, however eminent, do not; our responsibility is to discover the relevant legal principles, and apply the law as we find it."

Another locked-in syndrome sufferer, known only as "Martin", won his case for clearer prosecution guidance relating to the position of health professionals who assist in suicide cases.

Nicklinson died at his home Wiltshire in August 2012, aged 58, a week after losing a lengthy High Court battle for the right to end his life with a doctor's help.

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 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 fully conscious and aware of his predicament which he had described as "pure torture".

Former builder and father-of-two Lamb, from Leeds, said he was "absolutely gutted" by Wednesday's decision, but said he would carry on with the fight.

Lamb, who won the right to join the litigation to continue the High Court battle started by Nicklinson, wants a doctor to help him die in a dignified way after having been left immobile except for limited movement in his right hand by a car accident in 1990.

"I was hoping for a humane and dignified end -- this judgment does not give me that," Lamb said.

Care Not Killing (CNK), an alliance of anti-euthanasia campaign groups, welcomed the move to "comprehensively and completely reject the Nicklinson and Lamb cases".

"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.

During the appeal hearing in May the judges 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".