AUSTIN, TEXAS – A federal judge declared a same-sex marriage ban in conservative Texas unconstitutional on Wednesday, but will allow the state to enforce the law pending an appeal that will likely go to the U.S. Supreme Court.

Judge Orlando Garcia issued the preliminary injunction after two gay couples challenged a state constitutional amendment and a long-standing law. His ruling is the latest in a web of lawsuits across the country expected to end up in the Supreme Court next year.

"Without a rational relation to a legitimate governmental purpose, state-imposed inequality can find no refuge in our United States Constitution," Garcia wrote.

"These Texas laws deny plaintiffs access to the institution of marriage and its numerous rights, privileges, and responsibilities for the sole reason that Plaintiffs wish to be married to a person of the same sex," he wrote.

Garcia said the couples are likely to win their case and the ban should be lifted, but said he would not enforce his ruling pending one by the 10th Circuit Court of Appeals, which already is hearing two other states' cases. He also will give Texas time to appeal to the 5th Circuit Court of Appeals in New Orleans.

Garcia, appointed by President Clinton, is the first judge in the conservative 5th Circuit to reach such a decision. Texas Attorney General Greg Abbott, who also is the leading Republican candidate to succeed Gov. Rick Perry, promised to appeal the decision to the New Orleans court.

The ruling is the latest in a series of victories for gay rights activists following similar decisions in Utah, Oklahoma and Virginia.