Former High Court judge Michael Kirby has weighed into the same-sex marriage debate, describing the postal survey as "hurtful".
Speaking at a graduation ceremony at the University of Adelaide on Wednesday, Mr Kirby, who is gay, says the survey shows once again that gay Australians are singled out for discrimination and unequal treatment under the law.
He also lashed the federal parliament for "shamefully" failing to deal with the issue.
"To submit the rights of a minority of citizens of this country to the voting decision of a majority of others as a precondition to the mere possibility of having the issue considered in the normal way in parliament is very hurtful," he told the ceremony on Wednesday.
"It is hurtful to me. It is hurtful to my partner of 48 years."
Mr Kirby also pointed to similarities in the debate to the movement in the 1970s to repeal criminal laws against homosexuality.
"Sadly, many of those who in 1975 opposed the change in the criminal laws now have their modern counterparts," he said.
"They are opposed to contemporary moves to remove inequalities, specifically in our laws on civil marriage."
Mr Kirby also commented on last week's decision by the High Court to uphold the legality of the same sex postal survey.
"It held that the survey was legal," he said.
"But that does not make it any the less painful."
Mr Kirby said the debate over marriage equality showed the primitive nature of constitutional protections for equal treatment under the law that would force some Australians to "jump extra hurdles and face outright hostility".
"Now all we can do is proceed to vote yes and hope that our fellow citizens of good will do likewise," he said.
"So that by a resounding vote for equality, parliament can no longer neglect and delay a decision on this matter.
"As it has shamefully done throughout this year and may continue to do hereafter, whatever the vote in the survey."
Mr Kirby concerns over the survey came as former prime minister Kevin Rudd claimed his godson was punched in the face for "standing up for marriage equality".
The former Labor leader on Wednesday tweeted a photo of his godson with a bloody cut above his nose.
"So many warnings to Turnbull about what the postal vote cld unleash. Now my godson Sean has been punched standing up for #MarriageEquality," Mr Rudd wrote.