The NSW Greens will push for a motion in state parliament calling on the federal government to legalise same sex marriage.
Upper house Greens MP Cate Faerhmann says she will give notice on Tuesday of a motion urging federal MPs to amend the Marriage Act and legalise same-sex marriage.
On Monday two separate bills to make same-sex marriage legal were introduced in federal parliament - first by Australian Greens lower house MP Adam Bandt and independent Andrew Wilkie, and then by Labor's Stephen Jones.
Ms Faerhmann said the motion would allow state MPs to send a clear message to politicians in Canberra.
Similar motions have already been passed by the ACT and Tasmanian parliaments.
"I'm calling on all NSW MPs to help remove discrimination from our marriage laws," Ms Faehrmann said in a statement.
"The arguments against marriage equality are based on personal and religious beliefs that have no place in our civil marriage laws."
Alex Greenwich from Australian Marriage Equality welcomed the push.
"Just as the Tasmanian and ACT parliaments declared support for equality, the NSW Upper House now has a chance to send a message that will have a meaningful impact on the many same-sex couples in that state," he said in a statement.
Both Labor and Liberal MPs will be allowed a conscience vote when the motion is debated in the NSW Parliament.