The Catholic Church in Scotland has promised to fight the right-to-die bill launched by MSP Margo Macdonald.
The bill—in its early stages of consideration in the Scottish Parliament—aims to legalise assistance for those wishing to end their lives, and could lead to suicide clinics opening in Scotland.
The Catholic Church has said the legislation would “cross a moral boundary”.
A spokesperson said: “It would completely invert and threaten the relationship between patient and doctor and undermine the role of medicine in society.
“More importantly, such law is not needed. Physical suffering can now be controlled and alleviated with appropriate palliative care. Passing an assisted suicide law would threaten the weakest and most vulnerable among us, especially the elderly and the terminally ill.
"It would be a dramatic breach of Scotland’s longstanding commitment to protect and care for those most in need," the spokesperson added.
Mrs Macdonald, who suffers from Parkinson's, has estimated that if approved the legislation would be used by 50 Scots a year to end their lives. Using figures from countries where assisted suicide has been legalised, it would account for one in every 2,000 deaths.
Under the bill, to be eligible a person would either have been diagnosed as terminally ill, or be permanently physically incapacitated to such an extent as not to be able to live independently.
The church has also questioned whether the Scottish Parliament has the power to legislate in this area, suggesting that it would not compatible with human rights law.
A spokesperson said: “The European Convention on Human Rights recognises the right to life as inalienable, that it cannot be removed by any authority or relinquished by any person.”