By Jon Herskovitz
AUSTIN, Texas, Jan 7 (Reuters) - A U.S. federal appeals court this week will hear arguments on whether to strike down, or keep in place, same-sex marriage bans in three conservative southern states including Texas, the most populous state that does not allow gay couples to wed.
The same judicial panel that will consider the Texas case will also hear appeals on same-sex marriage bans in Louisiana and Mississippi, setting up a possible decision that could redefine same-sex marriage in parts of the U.S. South, where each state has passed legislation banning the practice.
The hearings before the U.S. Court of Appeals for the 5th Circuit begin in New Orleans on Friday and come as momentum builds nationwide to allow same-sex marriage, with 36 states legalizing gay marriage.
On the same day, Supreme Court justices will meet in private to decide whether to add cases on the issue to their calendar this term.
"My clients are gratified that there has been a lot of progress nationwide but they are still without the right to marry or to have their marriage recognized. There is an urgency in their view," said Neel Lane, an attorney for the two Texas couples seeking to overturn the state's ban.
The suit in Texas was filed on behalf of Austin residents Cleopatra De Leon and Nicole Dimetman, who were married in Massachusetts, and Victor Holmes and Mark Phariss, who were denied a marriage license when they applied in Texas.
In February, U.S. District Judge Orlando Garcia ruled the Texas ban was unconstitutional because it denied the couples equal protection under the law. Enforcement of the decision is on hold pending the appeal.
Texas has argued that states have the right to decide who can marry and it is in the state's interests to promote marriage between a man and a woman.
"Texas's marriage laws are rationally related to the State's interest in encouraging couples to produce new offspring, which are needed to ensure economic growth and the survival of the human race," state lawyers wrote in an appeals court filing.
In November, a U.S. district judge struck down as unconstitutional a same-sex marriage ban in Mississippi, overturning a measure that voters overwhelmingly approved about a decade ago.
In September, a U.S. district judge upheld a Louisiana ban on gay marriage in a break from a string of recent rulings against such bans in other states that followed a U.S. Supreme Court ruling in June 2013 expanding federal recognition of same-sex marriages. (Reporting by Jon Herskovitz; Editing by Alan Crosby)