Gay marriage is now firmly on the federal agenda following the Labor national conference decision to accept it as policy and to allow Labor MPs a conscience vote on the issue.
The Greens have introduced a same-sex marriage bill in the Senate, while two others have been proposed in the Lower House by Labor, Greens and Independent members.
But the chances of success are slim, with some members of the minority Labor Government opposed and Opposition Leader Tony Abbott making clear his view that Coalition MPs should vote against the proposal.
The couples meeting Gillard hoped they could soften Gillard's opposition.
"The main premise of the dinner really is to put a human face to the issue and just to discuss our own personal circumstances, our own lives with the Prime Minister," Melbourne butcher John Dini said.
His partner, Steve Russell, said it was only a matter of time before gay marriage became legal.
Meanwhile, the Queensland Labor Party expelled candidate Peter Watson after he admitted posting claims on the internet linking homosexuality to paedophilia and describing gays as social degenerates. Bligh said she was furious Watson had been endorsed.