A federal appeals court in California has refused to reconsider a landmark ruling that struck down the state's voter-approved ban on gay marriage.

The decision Tuesday by the 9th U.S. Circuit Court of Appeals clears the way for the case to go to the U.S. Supreme Court.

A three-judge panel of the California appeals court declared the state's same-sex marriage ban, known as Proposition 8, unconstitutional in February in a 2-to-1 decision.

Supporters of the ban said they would appeal to the nation's highest court if the full appeals court declined to revisit the case.

Proposition 8 passed in 2008 with 52 percent of the vote, just months after California had approved gay marriages.

Eight U.S. states and the District of Columbia have legalized same-sex marriage, but it is not recognized on the federal level.

Last week, a U.S. appeals court in Massachusetts ruled that the federal law defining marriage as a union between a man and a woman unconstitutionally denies benefits to gay couples who are legally married in the state.

Last year, U.S. President Barack and Attorney General Eric Holder said they would no longer defend the 1996 Defense of Marriage Act. President Obama declared support for gay marriage last month after previously saying his views were “evolving.”