(Adds background on litigation, adds Oregon judge denying standing to gay marriage foes)
By Laura Zuckerman
SALMON, Idaho, May 14 (Reuters) - A federal judge who struck down Idaho's ban on gay marriage as unconstitutional denied a request by the governor on Wednesday for a stay of the decision in the conservative Western state while the case is appealed.
The governor, Republican C.L. "Butch" Otter, called the ruling "regrettable" and vowed to petition a higher court to keep the state's gay marriage prohibition intact until the legal battle has run its course through the judicial system.
Separately on Wednesday, a federal judge in Oregon refused to grant legal standing to a national advocacy group seeking to defend a gay marriage ban under court challenge there after state officials declined to defend the voter-approved law.
A ruling on the Oregon lawsuit itself is expected soon.
In the Idaho case, U.S. Magistrate Judge Candy Dale overturned that state's ban on same-sex matrimony on Tuesday, saying it relegated gay and lesbian couples to second-class status in violation of constitutional guarantees of equal protection under the law.
Her decision was the latest in a flurry of recent court opinions striking down restrictions on same-sex marriage across the country - including bans in such socially conservative states as Utah, Oklahoma, Virginia and Texas.
Judge Dale in Idaho ordered enforcement of the gay marriage ban there to end by Friday morning. In denying the governor's request for a longer stay, she said the state's appeal was unlikely to succeed on its merits.
"Nor does the public interest favor preserving a status quo that deprives individuals of their constitutional rights," she wrote.
Marriage rights have already been extended to gay men and lesbians in 17 states and the District of Columbia in a trend that has gained momentum since the U.S. Supreme Court ruled last June that legally married same-sex couples nationwide are eligible for federal benefits.
That tally is expected to rise sharply if federal court decisions declaring bans in several states unconstitutional are upheld on appeal. (Additional reporting by Shelby Sebens in Eugene, Ore., and Teresa Carson in Portland, Ore.; editing by Steve Gorman and Matthew Lewis)