Donnie Herrington, left, and Justin Jones from Longmont, Colo., kiss outside the Boulder County Clerk and Recorder offices in Boulder on Thursday, June 26, 2014, after receiving a marriage license. 

(Photo: CPR/Pat Mack)
Colorado's ban on gay marriage faces a new challenge as six couples filed suit against the measure Tuesday in federal court.

It's the latest front in a multi-pronged attack on the constitutional provision, which was dealt a blow by the 10th U.S. Circuit Court of Appeals when it struck down a similar measure in Utah last week. A challenge to the provision is also being decided in state courts.

Lead attorney Mari Newman says a federal lawsuit is necessary because even if the state judge rules against the law, he could do it very narrowly by applying his decision only to Denver and Adams Counties, where the suit was filed.

Newman hopes to convince the District Court judge that last week's ruling in the Utah case means that Colorado county clerks must start issuing marriage licenses to same-sex couples, even though the appeals court has stayed its decision.

"I don't think that precludes other courts from standing up and doing the right thing," Newman says. "We're going to immediately file a motion for an emergency injunction so that the courts can instruct the governor, the attorney general and all of the clerk and recorders offices that they must not enforce these unconstitutional laws that deny marriage rights to same sex couples."

The couples involved in this latest lawsuit are all either unmarried, have civil unions or are married in other states that recognize same-sex unions. They cite the appellate court’s ruling in the Utah case last week in their argument that Colorado is violating their fundamental right to marry.

The lawsuit contends that 40 years after the U.S. Supreme Court struck down anti-miscegenation laws as unconstitutional, saying: "the State of Colorado discriminates against and denies its gay and lesbian citizens access to ‘the fundamental right to marry, establish a family, raise children and enjoy the full protection of [Colorado]’s martial laws’ in violation of the 14th Amendment to the United States Constitution."

Even as the plaintiffs filed their challenge in federal court, same-sex couples continue to receive marriage licenses in Boulder County. But the clock is ticking on a showdown between the Boulder clerk and Colorado's attorney general.

Clerk Hillary Hall announced on Tuesday that she will continue issuing marriage licenses to gay couples despite the threat of legal action by the attorney general.

Hall made the announcement after Suthers' office agreed to give her more time to consider asking the state Supreme Court to rule whether she has the authority to issue the licenses. The Attorney General's office says it is still open to seeking clarity from the courts, but will pursue legal action if Hall doesn't stop handing out the licenses by Wednesday.

The 10th Circuit stayed its ruled pending an appeal to the U.S. Supreme Court but Hall contends the stay doesn't forbid clerks from implementing the judges' decision.

"We believe they have made a clear statement about marriage being a fundamental right," Hall said when she started issuing the licenses last week. “And with that, we are moving forward to enable people who love each other, who've been prohibited by Colorado law for far too long, to have their union recognized as a marriage.”

This isn't the first time Boulder has granted marriage licenses to same-sex couples. In 1975, clerk Clela Rorex issued licenses to six couples, after being told by the district attorney that nothing in Colorado law forbade it. Those marriages were later invalidated by the state's attorney general, a fate that may be repeated this time. 

"[This] decision by the 10th Circuit Court of Appeals was stayed by the Court and has not gone into effect even in Utah, let alone in Colorado," Attorney General John Suthers said in a statement last week. "Any marriage licenses issued to same-sex couples in Colorado before a final court resolution of the issue are invalid."

The Attorney General is currently defending Colorado's gay marriage ban from a challenge in state court. Arguments in that case took place earlier this month and both sides are now awaiting a written ruling.