Prominent gay rights group Lambda Legal is ready to file its promised lawsuit to win gay marriage in New Jersey.'s blog The Auditor reported on Sunday that the group will petition the state Supreme Court on Thursday.

“We've lived the agony of defeat,” Steve Goldstein, CEO of Garden State Equality, New Jersey's largest gay advocate, told the website. “Now it's time for the thrill of victory.”

The challenge comes after senators killed a gay marriage bill in January. The defeat means that the Legislature isn't likely to revisit the issue over the next four years as Governor Chris Christie, a Republican who took the helm in January, does not support giving gay couples the right to marry.

In Lewis v. Harris, the New Jersey Supreme Court unanimously agreed that it is unconstitutional to deny gay and lesbian couples the rights granted to married heterosexual couples and ordered the Legislature to remedy the situation. Lawmakers responded with a civil unions law.

Gay activists say New Jersey's civil unions law is not equal to marriage.

Lambda Legal announced it would return to court the day after senators rejected the measure.

“The requirement to ensure equality for same-sex couples, established by the New Jersey Supreme Court in its decision in our marriage lawsuit in 2006, has not been met,” Kevin Cathcart, executive director of Lambda Legal, said in a statement.

“There is enormous, heartbreaking evidence that civil unions are not equal to marriage, and we will be going back to the courts in New Jersey to fight for equality. Too many families are at risk. We cannot wait any longer.”