Florida same-sex marriages
Same-sex couple plastic figurines are displayed during a gay wedding fair (salon du mariage gay) in Paris April 27, 2013. REUTERS/GONZALO FUENTES

(Reuters) - A federal judge in north Florida ruled on Thursday that county clerks statewide must issue marriage licenses to all same-sex couples who request them starting Jan. 6, the effective date of his decision to overturn Florida's ban on gay matrimony as unconstitutional.

The latest opinion by U.S. District Judge Robert Hinkle of Tallahassee addressed questions raised among court clerks about the reach of his previous ruling to legalize same-sex marriage, and whether it applied beyond Washington County and the two men named as plaintiffs in the case.

In a sharply worded four-page order, Hinkle said it was not the injunction he issued more than four months ago against Florida's gay marriage ban that compels statewide compliance, but the U.S. Constitution.

Ruling on the merits of the case on Aug. 21, Hinkle struck down a 2008 voter-approved amendment to the state constitution defining marriage exclusively as the legal union of one man and one woman. But he temporarily stayed his own ruling to give the state an opportunity to appeal.

"The defendants did that. They lost," Hinkle wrote. The stay is due be lifted Jan. 5, after which Florida will become the 36th state where gay and lesbian couples are free to marry.

The U.S. Supreme Court earlier this month declined to extend the stay.

Yet legal counsel to the clerks statewide interpreted the high court's order as applying only to Washington County. Clerks who married gay couples elsewhere in Florida were warned they risked fines and even jail for violating the state ban.

On Thursday the judge made clear his Aug. 21 ruling covered all applicants statewide, warning that county clerks could be held liable for civil damages, attorneys fees and court costs for refusing to abide by his decision.

The law firm representing the clerks responded with a statement advising them to "follow the judge's ruling for all marriage-license applications or face the consequences."

State Attorney General Pam Pondi said she welcomed the judge's "additional guidance" and said her office "will not stand in the way as clerks of court determine how to proceed."

Gay rights proponents hailed the latest decision.

"We look forward to Jan. 6, when couples who have waited for this day can finally be married," said Equality Florida, a Tampa-based gay advocacy group.