Vulnerable people will be at risk of abuse and pressure to end their lives prematurely if assisted suicide is legalised in the UK, an anti-euthanasia campaign group has said.
The warning from Care Not Killing follows the death of British man Richard Selley at the Dignitas euthanasia clinic in Switzerland on Friday.
Mr Selley, a 65-year-old former head teacher, suffered from motor neurone disease (MND) and had spent the last few years campaigning for a change to the law in Scotland, where he lived with his wife near Perth.
In a final video message before his death, Mr Selley called on MSPs to support an assisted dying Bill.
"I hope that members of the Scottish Parliament support an assisted dying Bill in the future," he said.
"I think the momentum for a change in the law is growing.
"It will be too late for me, but I hope that sometime soon people in my position will have the choice to have a peaceful death at a time of their choosing."
His wife Elaine confirmed his death online: "I am writing this post from my hotel room in Zurich. Richard died very peacefully at lunchtime today. His brother Peter and I were at his side.
"At Dignitas, in a clinically clean room, well appointed but devoid of any personal touches, we could feel all the love that has been shared with us over the years.
"The end was dignified and calm, exactly as Richard wanted. He had taken control of his own destiny."
Responding to news of his death, Dr Gordon Macdonald, Chief Executive of the Care Not Killing alliance, commented: "We are sorry to hear about Mr Selley's death. It is sad also that the death of Mr Selley is being used to try and justify a campaign that will rip up long held universal protections, by treating those who are terminally ill, disabled, or have chronic conditions differently in law.
"Such a change in the law will put vulnerable people at risk of abuse and of coming under pressure to end their lives prematurely."
There have been numerous attempts in the past decade and a half to change the law on assisted suicide in the UK. More recently, in 2015, proposed changes to the law were defeated in the Scottish Parliament by 82 votes to 36. In the same year, the House of Commons rejected a change to the law by 330 votes to 118.
Dr Macdonald said that the votes reflected a concern over the erosion of protections in the handful of countries that have legalised euthanasia and assisted suicide.
In Belgium, the country's relaxed euthanasia laws have come under scrutiny in light of some controversial decisions.
Earlier this year, a legal challenge was brought before the European Court of Human Rights by the son of a woman who suffered from depression and died by lethal injection despite being physically healthy.
Last year, a criminal investigation was launched into the decision to euthanise a 38-year-old woman two months after she was diagnosed with Asperger's syndrome.
Dr Macdonald said that in places where euthanasia has been legalised, there was evidence that people were ending their lives out of a fear of being a burden on their families or carers, and that in some instances, people had been refused life-saving or life-extending hospital treatment while being offered assisted suicide.
He voiced concern that assisted dying laws in places like the Nethelands and Belgium were "operating way beyond their original intent" to cover people who are "not mentally competent".
"This is why not a single doctors group or major disability rights organisation supports changing the law, including the British Medical Association, the Royal College of General Practitioners, the Royal College of Physicians, the British Geriatric Society and the Association for Palliative Medicine," he said.