The state of Texas sued the U.S. Labor Department over a rule that would grant family medical leave protections to all married same-sex couples, saying it violates the rights of states that don't recognize gay marriage.
The lawsuit filed on Wednesday in federal court in Wichita Falls, Texas is the first challenge to the department's rule, which is set to take effect on March 27.
The rule will require companies to follow the marriage laws of the states in which their employees were wed, rather than where they reside, for the purpose of applying the federal Family and Medical Leave Act. That law requires employers to grant workers unpaid leave after giving birth or to care for sick family members.
President Barack Obama last year first announced the so-called "place of celebration" rule in the wake of the U.S. Supreme Court's decision in June 2013 in United States v. Windsor, which said the Defense of Marriage Act, the federal law that defined marriage as a heterosexual union, was unconstitutional.
In the lawsuit, the office of Texas Attorney General Ken Paxton, a Republican, says the rule actually violates the Windsor decision because it held that the federal government cannot interfere with the states' marriage laws.
"Attempts by the Obama administration to disregard the will of our citizens through the use of new federal rules is unconstitutional and an affront to the foundations of federalism," Paxton said in a statement.
The lawsuit, which says the rule violates a constitutional clause that requires states to respect each other's laws, seeks a temporary injunction of the rule pending the outcome of the case.
The Labor Department did not immediately respond to a request for comment on Thursday.
The rule has been hailed by gay rights groups and attorneys who represent workers and has divided employers. Some companies say it will impose a hefty burden on them to know the relevant laws and employees' personal information; others say the opposite, that a uniform policy will ease the financial stress of complying with a patchwork of laws.
The Supreme Court next month is scheduled to consider for the first time whether there is a constitutional right to marry. A ruling in favor of same-sex couples would likely moot the family leave issue.
The case is Texas v. United States of America, U.S. District Court for the Northern District of Texas, No. 7:15-cv-0056.
(Reporting by Daniel Wiessner in Albany, N.Y.; Editing by Alexia Garamfalvi and Jonathan Oatis)