The U.S. Supreme Court has set April 28 as the date it will hear the case on whether Washington State can release the names of people who signed petitions supporting a domestic-partnership referendum. Last November voters approved Referendum 71, which upheld the law expanding domestic-partnership rights for same-sex couples.

The hearing before the high court represents the culmination of an appeals process in which domestic-partnership opponents have sought to obscure their role in putting Referendum 71 on the ballot.

“Protect Marriage Washington unsuccessfully opposed a new law giving gay couples expanded rights,” reports the Associated Press. “The group wants to shield petition-signers' names from public release, saying it fears harassment by gay-rights supporters.”