A paralysed man who challenged the law which criminalises assisted suicide has died, aged 65.
Paul Lamb was severely injured in a car crash in 1990 and was left with no function from the neck down aside from limited movement in his right arm.
Mr Lamb, from Leeds, had lived with chronic pain as a result of his paralysis and required 24-hour care.
Humanists UK, which announced the news of Mr Lamb's death, said he had left a "fierce legacy of campaigning".
Mr Lamb took on several legal challenges over the current law on assisted suicide, which he said breached his human rights.
He said he wanted to be able to end his life at a time of his choosing.
Assisting a suicide is a criminal offence and carries a maximum 14-year prison sentence.
In 2014, Mr Lamb and the family of fellow right-to-die campaigner Tony Nicklinson lost their case at the Supreme Court, but judges said parliament should be given the opportunity to re-consider the law.
Five years later, he lost a High Court bid to challenge the law on assisted suicide, with two judges telling him his case was "unarguable" and should not proceed to a full hearing.
They said it was a matter for Parliament and not for the courts.
Prior to his accident, father-of-two Mr Lamb worked as a builder and was a champion greyhound racer.
Following his death, carer Francesca Hepworth said: "For years, Paul grappled with his condition and faced increasing pain, discomfort, and distress.
"But throughout it all, what scared him most was his utter lack of control, and the prospect of his pain becoming too much to handle."
She added: "Paul was resolute in his belief that nobody should be forced to suffer, and determined to keep fighting to change the law."
Humanists UK, a national charity which worked with Mr Lamb, said his death was a "loss to us all".
Andrew Copson, its chief executive, said: "Paul Lamb was a tireless advocate for the right to die who dedicated his life to championing choice for those with terminal or incurable illnesses.
"He leaves behind a fierce legacy of campaigning, which we are determined to continue in his honour."
Dr Gordon Macdonald, chief executive of Care Not Killing, which promotes palliative care, described Mr Lamb as a "dedicated campaigner who challenged all those who oppose assisted suicide and euthanasia to set out our concerns".
He added: "Our thoughts are with his family, friends and all those who are struggling with bereavement at this time."