A new bill to legalise assisted dying will be lodged at the Scottish Parliament, the BBC has learned.
The proposals – brought forward by Liberal Democrat MSP Liam McArthur – aim to introduce the right to an assisted death for terminally ill, mentally competent adults.
Previous attempts to change legislation in Scotland have failed.
A cross-party steering group of MSPs have outlined their support of the bill in an open letter.
The bill will be lodged at Holyrood on Monday and it is understood a consultation on its contents is expected to take place in the autumn.
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Those who argue against a change in the law say it would undermine palliative care and the risks are too high – claiming it would put pressure on vulnerable patients.
Mr McArthur told BBC Scotland he believed people should be able to access safe and compassionate assisted dying if they choose, rather than endure a prolonged and painful death.
He said the bill contains "strong safeguards".
"The current blanket ban on such assistance is unjust and causes needless suffering for so many dying people and their families across Scotland," he said.
"If you have reached the limits of palliative care and face a bad death, none of the current options available to you in Scotland represents an acceptable alternative to a peaceful, dignified death at home."
The open letter of support for the bill was signed by 12 MSPs.
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They are Karen Adam, Ariane Burgess, Jackson Carlaw, Katy Clark, Rachael Hamilton, Patrick Harvie, Liam Kerr, Gillian Mackay, Rona Mackay, Fulton MacGregor, Lorna Slater and Paul Sweeney.
It states: "The current law does not work and should be replaced with a safe and compassionate new law that gives dying people the rights they need to have a good death at a time that is right for them.
"We know there is a problem and it is incumbent upon us to provide a solution."
The bill's "safeguards" include a number of criteria for qualification for assisted dying – for example people have to have a terminal illness and a certificate of mental competency.
They also have to be an adult who lives in Scotland only.
Warning: People may find some of the content below distressing
'Nobody should have to witness it'image captionFrom left to right – Zoe Black, Sarah Drummond and Victoria Burns
Zoe Black, Sarah Drummond and Victoria Burns were the main carers for their mother Heather Black when she died earlier this year – they say they found the experience "absolutely cruel".
Diagnosed with oesophageal cancer in March, Heather's health deteriorated quickly until her death on 14 May.
Her daughters say the final days before her death were "gruesome" – they watched her cough and choke as she vomited blood and parts of a tumour, all while on an "unprecedented" volume of pain medication.
Zoe said: "It's not right that we were expected to watch this woman who had been absolute dynamite her whole life be reduced to a shrunken mess in the bed, covered in tumour and foam, her insides out.
"It's horrendous and nobody should witness it."
Before those final, painful days, Sarah described Heather's care as "manageable", saying she and her sisters could chat and laugh with her.
But she said there was a "turning point" in the illness when Heather made it clear she wanted to die – something that chimed with her lifelong wishes of retaining dignity at the end of her life.
"She was really scared and was crying a lot and she just wanted it to end, for the pain to be over," Sarah said.
"We knew she wanted to die. She really didn't want her life to end the way that it did."
'They do not want to die'
Opponents refer to the issue as "assisted suicide" and say it is open to abuse, coercion and exploitation as well as putting pressure on vulnerable people.
However, Ally Thomson, director of Dignity in Dying Scotland, said there was "huge support" among Scottish people and in parliament for the bill and argued that a blanket ban created injustice for suffering families.
She called it a "watershed moment" for dying people in Scotland.
image captionMs Thomson said there was a body of evidence showing assisted dying was a safe choice
"I would like anybody who would describe this as assisted suicide to speak to the people who have spoken out so bravely about their own experiences of how they are suffering just now," she said.
"They do not want to die but that choice has been taken from them. What they don't want is a protracted, painful death."
Ms Thomson pointed to countries such as New Zealand, Australia and the USA where assisted dying is legal in parts.
"The evidence and research from those places shows that this is a safe choice, a compassionate choice, it is not in any way an alternative to palliative care," she added.
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