Scottish health secretary Humza Yousaf has been warned of the potential for harm if assisted suicide is legalised in Scotland.
The warning comes in an open letter signed by 175 healthcare professionals.
They include David Galloway, the recently retired consultant surgeon and former president of the Royal College of Physicians and Surgeons in Glasgow, and Professor Marie Fallon, a researcher in palliative medicine at Edinburgh University.
The letter follows proposals brought forward last month by Liberal Democrat MSP Liam McArthur, and has been sent to the health secretary as part of a campaign against the Bill launched by Our Duty of Care (ODOC), coalition of healthcare workers.
They call on the Scottish government to preserve life, and warn of the erosion to supposed safeguards in countries like Canada, where assisted suicide is already legal.
"We write with great concern regarding the introduction of a Bill to legalise assisted suicide in Scotland," they say.
"The shift from preserving life to taking life is enormous and should not be minimised. The prohibition of killing is present in almost all civilised societies due the immeasurable worth of every human life.
"Everyone has a right to life under Article 1 of The Human Rights Act 1998 such that no one should be deprived of that life intentionally."
The letter goes on to say that promised safeguards would not be enough to protect the vulnerable from abuse.
It further warns that a change to the law would undermine public trust in physicians and "send a clear message to our frail, elderly and disabled patients about the value society places on them as people."
"The prohibition of killing is the safeguard. The current law is the protection for the vulnerable," the doctors write.
They continue, "Far from one person's decision affecting no one else, it affects us all. Some patients may never consider assisted suicide unless it was suggested to them.
"The cruel irony of this path is that legislation introduced with the good intention of enhancing patient choice will diminish the choices of the most vulnerable.
"One in 60 deaths in Belgium now occur with no consent from the patient- those in coma, confused or the elderly - are euthanised because their lives are considered not 'worth living'."
The letter has been welcomed by Dr Gordon Macdonald, chief executive of the Care Not Killing (CNK) alliance of pro-life organisations.
CNK helped defeat two previous assisted suicide Bills at Holyrood in 2010 when MSPs voted 85-16 against, and again in 2015 when the vote was 82-36 against.
First Minister Nicola Sturgeon voted against both Bills and said before the 2015 vote: "I voted against it last time (2010) and I haven't been convinced of assisted suicide this time either. A major stumbling block is the issue of sufficient safeguards. I believe we should support people to live and I am therefore in favour of good quality palliative care."
Welcoming the letter from doctors, Dr Macdonald said: "For over 2,000 years the underlying ethic of medicine has been to 'do no harm', preserve life and alleviate suffering by seeking to heal or palliate.
"For doctors to facilitate the deaths of their patients is to betray their professional responsibilities and will prepare the ground for more pressure to be applied on disabled people, the elderly and others who are in a vulnerable situation to end their lives prematurely."
Dr Macdonald said he feared any legalisation of assisted suicide would open the door to considerations about budgets and savings taking precedence.
"The prospect of financial pressures corrupting medicine and pressurising people into an early death should not be overlooked," he said.
"Rather than legalising assisted suicide, we should be investing more resources to ensure everyone who needs it in Scotland can access proper palliative care."