He said he also had ethical concerns about the risk to vulnerable people if the Bill passed. But his Labour colleague, Dunedin South MP Clare Curran, will vote for change — at least on the first reading.
"I will support it [on its first reading] to select committee.
"Agree that it’s timely for Parliament to again scrutinise the issue. I’ll make my final decision based on the outcome of the select committee process."
Dr Clark said he supported the health select committee investigation into euthanasia. It had been a productive process involving a large part of the community in a "mature discussion".
"[The Bill] risks distracting from what is already a good select committee process.
"It is a political stunt that will give profile to [Act New Zealand leader] David Seymour."
Green Party co-leader Metiria Turei, of Dunedin, said she needed to scrutinise the proposed law before forming a view, but had previously supported change. A spokeswoman for National list MP Michael Woodhouse, of Dunedin, said he was opposed to euthanasia.
Waitaki MP Jacqui Dean said she was "open-minded" and would consider the Bill carefully before deciding.