Tony Abbott has admitted he is conflicted over the gay marriage debate given his sister, Christine Forster, is in a same-sex relationship.
But the Opposition Leader says says he and his sibling "respectfully disagree" in their opposing views.
Ms Forster is a vocal supporter of gay marriage, while her brother this week led the Coalition in a bloc "no" vote in two separate bills seeking to amend the marriage act to include same sex marriage.
Mr Abbott told morning television he was a "traditional conservative person" but he was conflicted over the gay marriage debate "because people close to me obviously have a different view and would like to get married, even though they're a same-sex couple".
"In the end it's possible to respectfully disagree and that's what happens inside the Abbott family - Chris and myself respectfully disagree," he said.
The House of Representatives voted down Labor MP Stephen Jones' bill 98-42 on Wednesday, and the Senate rejected a similar bill – proposed by Labor senator Trish Crossin and co-sponsored by three other senators – 26-41 on Thursday afternoon.
Mr Abbott said it was a "fairly decisive vote" and it was time to "let the dust settle" before considering what, if any, next steps should be on the issue.
His statement can be seen as a warning shot across the bow to the Opposition Chief Whip, Warren Entsch, who has signalled his intention to push for the legalisation of civil unions as an alternative.