Turnbull told the parliament that this argument presumes Australians "cannot be trusted to have a civil conversation".
"[Shorten is saying] that the Australian public are so immature, so unbridled, so reckless that they cannot be trusted to have a debate and make a decision on this issue," he said.
In an opinion piece for The Australian published last month, Liberal MP Tim Wilson said Shorten's comments had overstepped the mark.
"Now let me be blunt, Mr Shorten," Wilson wrote.
"While such lines may sound good in a political pointscoring war, it demonstrates a failure to understand the issue and the responsibility he carries with his office. Suicide is not a political plaything. It’s serious."