A judge in Connecticut will today enter the final judgment in a case that allows same-sex marriages.
Immediately after the hearing gay and lesbian couples will be able to get marriage licences.
The Supreme Court of Connecticut overturned a ban on gay marriage last month, ruling that stopping same-sex partners from marrying was a violation of their constitutional rights.
There have been more than 2,000 civil unions in the US state since they were legalised in 2005.
“I would bet that the majority of those people would change the civil unions to marriage,” said Anne Stanback, president of gay rights group Love Makes a Family. “I think that you have people who’ve waited to get married and have not had civil unions.”
The judgement followed a case that began four years ago when eight same-sex couples sued the state arguing that by not allowing them to marry, the state discriminated against them in volitional of their constitutional rights.
The majority 4-3 opinion said that the “segregation of heterosexual and homosexual couples into separate institutions constitutes a cognisable harm.”
Justice Richard Palmer added: “our state scheme discriminates on the basis of sexual orientation… and the state has failed to provide sufficient justification for excluding same sex couples from the institution of marriage.
“In accordance with our conclusion that the statutory scheme impermissibly discriminates against gay persons on account of their sexual orientation, we reverse the trial court’s judgement and remand the case with direction to grant the plaintiffs’ motion for summary judgement.
“Interpreting our state constitutional provisions in accordance with firmly established equal protection principles leads inevitably to the conclusion that gay persons are entitled to marry the otherwise qualified same-sex partner of their choice,” Justice Palmer declared.
“To decide otherwise would require us to apply one set of constitutional principles to gay persons and another to all others.”
Republican state Governor Jodi Rell said that although she disagreed with the judgement, she would uphold it.
“I do not believe their voice reflects the majority of the people of Connecticut,” the Governor said.
“However, I am also firmly convinced that attempts to reverse this decision, either legislatively or by amending the state Constitution, will not meet with success.”
A similar state Supreme Court in California in May allowed gay marriage, and an estimated 18,000 gay and lesbian couples have taken advantage of their new rights.
Voters approved a ballot measure last week that seeks to deny gay couples their marriage rights by changing the state constitution to define marriage as only between a man and a woman.
Gay rights groups are challenging the validity of Proposition 8 in court.
Californian gay and lesbian couples can still register domestic partnerships but cannot get married.