The lawsuit filed by seven same-sex couples and several of their children is the latest move in a decadelong effort by gay-rights groups to win marriage rights in New Jersey.
In 2006, the state's top court ruled unanimously that gay couples deserved equal treatment under the law and returned a 4-3 decision that those rights did not have to be called marriage. Lawmakers responded by creating civil unions, which offer the legal protections but not the name of marriage.
In the latest lawsuit, the couples and their children say civil unions do not create the equality that the state court mandated in 2006.
"We are pleased that the New Jersey Superior Court will allow us to show how civil unions fail to provide to same-sex couples the equality promised by both the New Jersey Constitution and the 14th Amendment of the U.S. Constitution," Jon Davidson, legal director at Lambda Legal, said in a statement Tuesday.
"We look forward to presenting a complete record of the discrimination that New Jersey's same-sex couples and their children face because of their relegation to civil unions rather than marriage," he said.
Gay rights groups also have been trying to persuade lawmakers to recognize same-sex marriage. Tuesday's ruling came five days after the Legislature passed a measure to legalize same-sex matrimony and four days after Gov. Christie vetoed it.
The majorities that passed the bill fell short of the two-thirds required for an override, but an override vote could come as late as January 2014, when the legislative session will end.