First Minister John Swinney has said he will not support a bill which would allow assisted dying in Scotland.
Legislation to allow terminally-ill people to take their own life is being put forward at the Scottish Parliament by the Liberal Democrat MSP Liam McArthur and will be voted on by MSPs on 13 May.
If the bill passes it would allow a patient to request medical assistance to end their life, but only if they had a terminal illness and had been ruled mentally fit to make the decision by two doctors.
A Holyrood committee which is scrutinising the legislation has said members should vote at the first stage of the process as a “matter of conscience”.
It is thought Swinney’s position may sway some undecided MSPs, particularly in his own party.
The stage one vote next week will be the third time in the Scottish Parliament’s history that a vote will be held on this issue.
In 2010, the End of Life Assistance (Scotland) Bill failed, followed by an attempt in 2014 with the Assisted Suicide (Scotland) Bill.
The terminology may have changed, but the principle is much the same.
The first minister said in October last year that he had “not come to a final view” on the issue but added that the initial proposed age threshold of 16 was “a very significant issue in my mind”.
Liam McArthur has since said he would raise the minimum age in proposed legislation from 16 to 18.
The Lib Dem MSP said he had considered the matter “very carefully” and the change was in line with legislation in the US, Australia and New Zealand.
He has urged MSPs to vote in favour of the bill and help create “the most compassionate, safe and suitable law for Scotland”.
MPs in England and Wales voted in favour of a bill to allow assisted dying last year, by 330 votes to 275.
Like the UK parliament, Holyrood will hold a free vote on assisted dying – which means MSPs will not be instructed on how to vote by their parties.