Several of the gay couples whose 2006 landmark case resulted in civil unions for New Jersey are returning to court.

In Lewis V. Harris, the state's top court 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 by enacting a civil unions law modeled after Vermont's law. (Vermont has since approved marriage for gay couples.)

After lawmakers rejected a gay marriage law last year, the couples asked the New Jersey Supreme Court to consider new arguments in their legal battle. But the court declined, citing a need for a trial record.

On Wednesday, the couples are expected to return to court. In the filing, five of the seven couples are joined by their children.

Gay groups argue civil unions are inferior to marriage.

“The separate and inherently unequal statutory scheme singles out lesbians and gay men for inferior treatment on the basis of their sexual orientation and sex and also has a profound stigmatizing effect on them, their children and other lesbian and gay New Jerseyans,” lawyers wrote in their filing.

Steven Goldstein, chair of Garden State Equality, the state's largest gay rights group, said last June that the court's decision against re-opening the case extended the state's “caste system.”

“Because of the legislature's inability to act and the Supreme Court's decision today, New Jersey continues in a caste system where an entire people are thrown aside into a profoundly inferior status, spit on, dumped on, utterly degraded, by hospitals and employers who mock the term 'civil union,'” Goldstein said.

The action comes less than a week after neighboring New York legalized gay marriage without a court order.