(CNN) -- The California Supreme Court unanimously agreed Wednesday to take up the issue of whether state or county officials have the authority to defend Proposition 8, the 2008 initiative defining marriage as only between one man and one woman, court spokeswoman Lynn Holton said.
The state court decision came in response to a request by the U.S. 9th Circuit Court of Appeals to examine the question of state law.
The appeals courts in San Francisco last month delayed indefinitely consideration of the constitutionality of the state's voter-approved ban on same-sex marriage, so that the state supreme court could examine the standing issue.
Top state officials -- including former attorney general and current Governor Jerry Brown -- have refused to defend the ban in court. The case, Perry v. Schwarzenegger, is expected to land eventually in the U.S. Supreme Court.
The California Supreme Court set up an expedited schedule in order to hear oral arguments as early as this September.
Same-sex marriage is currently legal in five states --- Massachusetts, Connecticut, Vermont, Iowa and New Hampshire -- and in the District of Columbia. Civil unions are permitted in New Jersey.