The Human Rights Commission and two other groups want to join a legal challenge by a terminally ill woman seeking the right for a doctor to help her die without criminal prosecution.
Lecretia Seales, 41, is dying from brain cancer and believes it's a "fundamental human right" to be able to choose to end her life with medical assistance, if she wants to, before her suffering becomes intolerable.
In a legal first in New Zealand, the senior legal and policy adviser at the Law Commission filed a statement of claim in the High Court seeking a ruling to determine whether her GP could lawfully administer a lethal dose of drugs.
Assisting suicide is a crime punishable by up to 14 years in prison but Ms Seales' case relies on the provisions in the New Zealand Bill of Rights Act that protect the rights to not be deprived of life or subjected to cruel treatment.
If successful, the bid would allow the doctor to euthanise Ms Seales because of her specific circumstances and would not set a precedent. But a favourable High Court ruling would allow others to follow suit and potentially send a signal to Parliament for further law reform.