Campaigners have warned of "huge risks to the most vulnerable" if Scotland legalises assisted suicide.
Legislation is being introduced to the Scottish Parliament by Lib Dem MSP Liam McArthur who wants assisted suicide made legal for terminally ill adults.
Similar legislation is being considered in Westminster.
In both nations, supporters have promised stringent safeguards but Michael Veitch, parliamentary officer at Christian charity CARE, said no measures could adequately protect the vulnerable.
He called the latest attempt to change the law "hugely dispiriting".
"Both Holyrood and the UK Parliament have rejected this kind of legislation in recent years and for good reason. It poses huge risks to the most vulnerable in Scottish society," he said.
"This law will not just affect the small number of individuals who might choose to access assisted suicide. It will affect every person living with a terminal illness, fundamentally alter the doctor-patient relationship, devalue disabled people's lives, and undermine wide efforts to prevent suicide.
"There can be no adequate safeguards. Providing a terminal prognosis is fraught with uncertainty. Vulnerable patients can be coerced. And the experience of other jurisdictions shows that an incremental extension of the law is inevitable.
"Sadly, this legislation comes after a renewed campaign driven by hyperbole, not by evidence and information. We hope that parliamentarians will be guided by the evidence in the forthcoming debate and opt to uphold current provisions.
"There are far better and more ethical ways to help patients at the end of life than allowing lethal drugs to be prescribed on the NHS."
Dr Calum MacKellar, Director of Research of the Scottish Council on Human Bioethics, echoed these concerns, saying the legalisation of assisted suicide would lead to an inequality in human value.
"This move requires society to accept that some lives are unworthy of life. And it means the worth of some lives is no longer considered to be equal to that of other lives," he said.
"When a society no longer believes in the equal worth of all lives, it is on a very dangerous road and can no longer be considered civilised."
Health Secretary Matt Hancock said there were risks to changing the law during a meeting of the All Party Parliamentary Group on Dying Well.
"I think everybody would agree that the current law around this area is complicated, but there are risks to changing it as well as there being problems with the way that the current law is drafted," he told the group last week.
He added: "The government's position is that we don't we don't take a view on a change in the law...because we think that these questions are for Parliament.
"I think as Health Secretary in a way, I see myself as the parliamentarian whose job it is to make sure that the debate is a, is a high-quality one when it comes."
During the meeting, former Paralympian Baroness Tanni Grey-Thompson warned of the impact on disabled people and questioned the idea of safeguards.
"Frailty and illness and especially illness and disability are often wrongly used interchangeably," she said.
"Some would say the six months prognosis that is included in the bill would exclude disabled people. But there are many disabled people for whom it could be reasonably argued they have six months left to live.
"Most people don't realize the daily grind that disabled people face, and I recognize I have a degree of privilege in my life, but I've lost track of the number of people who have asked me, have I thought about ending my life because they assume that my life is so terrible and tragic...
"People say to me that they couldn't bear it if they were incontinent. Well, I am. And it is not even vaguely the hardest thing in my life. If you banned catheters that might change how I was able to live. But people's underlying view of disability is inherently negative."
"I have spent most of my life arguing for choice and inclusion, but we have to recognize that a significant number of disabled people have very, very little choice in their lives and right now, disabled people are spending a lot of the time fighting to live and survive as opposed to asking to die...I would just ask people to think about the impact on disabled people. And the idea that we are somehow in the waiting room for assisted suicide to have us included."