Supporters of Proposition 8 have lost the latest legal round to keep private the names of donors to the 2008 amendment that banned gay marriage in California, the AP reported.

ProtectMarriage.com, the coalition of mostly religious groups that sponsored Proposition 8, and the National Organization for Marriage (NOM), the country's most vociferous opponent of gay marriage, had sued to block their campaign finance records from being made public.

After a brief hearing on Thursday, U.S. District Judge Morrison England Jr. ruled against the groups, Mollie Lee, a lawyer in the San Francisco City Attorney's office said. A written opinion is expected shortly.

NOM and ProtectMarriage.com filed the lawsuit in 2009, arguing that their donors were subjected to ridicule, protests and harassment after their names were made public by the Secretary of State.

The ruling comes just days after opponents of a Washington law that recognizes gay and lesbian couples with nearly all the protections of marriage lost their legal case to keep private the names of signers of a petition that attempted to repeal the law.