Western Australian Legislative Council member Nick Goiran says "it is a legal impossibility to create a safe euthanasia regime".
The Western Australian parliament is debating the Voluntary Assisted Dying legislation in its upper house after it passed the state's lower house.
Mr Goiran said it can't be safe due to "medical negligence law, lessons in contract law, doctor bias and what has happened in other jurisdictions around the world".
"No one has been able to explain to me why Western Australian's should have a more dangerous system than Victoria," he said.
Mr Goiran believes "elder abuse is a particular problem" in WA due to what he terms "inheritance impatience syndrome".