Gillard is not married to long-term partner Tim Mathieson but says that doesn't mean they aren't in a committed relationship.
"I think you can have a relationship of love and commitment and trust and understanding that doesn't need a marriage certificate associated with it," Gillard told ABC TV last night.
"That's my life experience - so I'm speaking from that life experience."
Gillard was responding to a question about her opposition to gay marriage from Sydney plumber and Vietnam veteran Geoff Thomas.
Thomas, whose son Nathan is gay, in 2010 asked Opposition Leader Tony Abbott on national TV when he would overcome his ignorance and start treating homosexuals with the respect they deserved.
He said Gillard was standing side-by-side with Abbott and the "extremist" Australian Christian Lobby.
But the PM stressed Labor had amended federal laws to "equalise the treatment of same-sex couples" when it came to superannuation and social security benefits.
Gillard said it was her "deeply" held view that the long-standing cultural institution of marriage shouldn't be changed but rather "new traditions and norms" were needed for homosexuals.
Labor MPs will be allowed a conscience vote on gay marriage when legislation is put before the parliament.
Gillard yesterday said she suspected "large numbers of them won't vote the same way as me".
Article from TVNZ.