Lambda Legal and Garden State Equality have scheduled a new conference for Thursday morning in Trenton to announce their action.
It comes barely two months after a stinging defeat in the New Jersey State Senate, when several legislators apparently backtracked on earlier promises and failed to pass a Marriage Equality law.
The advocates are prepared for a tough battle. "It's hard to tell [how long this will take]," said Lambda Legal spokeswoman Lisa Hardaway in New York.
But the organization will be building on a 2006 decision by New Jersey's highest court that ordered legislators to pass either a Marriage Equality law or an equivalent Civil Union law that gave gays identical rights. Legislators chose civil union.
Ever since, gay marriage advocates have argued civil union doesn't work, that it's not recognized by hospitals, doctors and employers. And in fact, several senators who voted against gay marriage in January admitted that it might not work, but they weren't willing to go with a law that used the word 'marriage.'
So now it turns to New Jersey's Supremes.
In 2006, after a Domestic Partnership law had been passed but before the civil union law was approved by legislators, the Court's decision started off by saying "the unequal dispensation of rights and benefits to committed same-sex partners can no longer be tolerated under our State Constitution."
But in a lengthy decision, the Court finally decided that it should be up to the Legislature to determine if full rights were to be given with the word "marriage" or with the term "civil union."
In their 2006 opinion, the Court wrote "Here is the perplexing question -- 'what's in a name?' -- and is a name itself of constitutional magnitude after the State is required to provide full statutory rights and benefits to same-sex couples?"
It was a divided court that handed down this decision, but not in the way gay marriage foes would hope. Three of the seven justices wanted to go bypass the legislature and simply rule that gay marriage would be law in New Jersey.
"The Legislature gave them every legal right," said Len Deo of the Family Policy Council.
Deo said he is hoping the High Court refers this to a lower court.
"There could be a new court by the time it gets to the Supreme Court," said Deo, referring to the turnover that normally occurs, and the possibility that Republican Governor Chris Christie may appoint some more conservative judges.
Gay marriage advocates are hoping the Supremes will take their case immediately for the same reason. And while there has been some turnover since the 2006 decision, the new appointees all came from Democrat Jon Corzine before he left office in January.
"It's hard to tell," said Lambda Legal's Hardaway, referring to whether the High Court will bypass the lower courts or not.
Gay marriage is legal in the District of Columbia and five states; Connecticut, New Hampshire, Massachusetts, Vermont and Iowa. It was repealed last November in Maine, and is banned by law or constitutionally in dozens of states.