Abbott rules out referendum on same-sex marriage

PRIME Minister Tony Abbott has ruled out a national referendum on marriage equality, saying it was the "preserve of the Commonwealth Parliament".

Mr Abbott made the comment after Ireland voted in favour of same-sex marriage last week, and as a push for a conscience vote continued in Canberra.

But he said referendums were held when there was a proposal to change the constitution.

"I don't think anyone is proposing to change the constitution in this respect," he said.

Earlier on Monday, Mr Abbott's sister and Sydney City Councillor Christine Forster said she supported a conscience vote in the same vein as that held in the United Kingdom recen-tly. While the Greens and Liberal-Democrat Senator David Leyonhjelm support marriage equality, the issue has divided the Coalition and Labor for several years.

Opposition leader Bill Shorten supports marriage equality, and a party position on a conscience vote under his leadership is expected to emerge from Labor's national conference next month.

Sen Leyonhjelm has said he believed there were Liberal and Labor MPs who would support marriage equality, as long as a bill did not come from the Greens.