Same-sex marriage is inevitable and a critical step towards reducing discrimination, MPs supporting a NSW bill on the issue say.
The state's parliament is on Thursday debating the bill, introduced by a cross-party working group.
Passing it would eliminate discrimination and help young people feel comfortable about their sexuality, Labor MLC Penny Sharpe says.
"There are still young people in this state who get up every day hoping no one notices or no one asks if they are gay, a fag, a poof, a lezzo or words much, much worse," she said.
"I want every person who has struggled simply for being who they are ... to know there are people in the community who won't accept this discrimination."
Labor's Walt Secord said same-sex marriage was "inevitable" given the growing support in the community. Legislative change would ensure NSW keeps up with a "contemporary sense of justice," he said.
But not everyone is supportive.
Christian Democratic MP Fred Nile maintained the traditional, heterosexual definition of marriage needed to be upheld.
"Marriage is a sacred institution," he said.
"It's always been, for thousands of years, between a male and female."
He said it was "illogical" to suggest same-sex marriage would strengthen the institution by broadening its appeal.
Meanwhile, Premier Barry O'Farrell has penned an opinion piece in Sydney's Star Observer restating his support for national same-sex marriage laws.
"To be truly equal, same-sex marriages should enjoy the same legal status and recognition as other marriages," he wrote.
"Only a change to the federal Marriage Act will deliver that equality."
The bill's second reading continues.
