Fairfax newspapers say the annual NSW Labor Party conference next month is likely to vote in support of gay marriage.
NSW upper house MP Penny Sharpe says Labor has a proud history of supporting equality and a priority for the party is to eliminate sources of discrimination against same-gender couples.
Labor state conferences in Queensland, Western Australia and South Australia have already adopted similar motions.
If successful the NSW vote will increase pressure on Julia Gillard to legalise single sex unions.
The Prime Minister has long stated her opposition to gay marriage.

