Letting the voter-approved ban on gay marriage stand, California's Supreme Court on Wednesday agreed to hear several legal challenges against the ban. Though an earlier decision by the same court in May had opened marriage to same-sex couples in the state, gay couples are legally no allowed to resume marrying before it rules anew.

The court has accepted three lawsuits seeking to nullify Proposition 8 - a voter-approved constitutional amendment that overruled the court's decision that legalized gay marriage. It is being claimed that the measure abridges the civil rights of a vulnerable minority group, and that voters alone should not have the authority to enact a constitutional change as significant as this.

In urging the Supreme Court to consider whether Proposition 8 passes legal muster, gay rights groups and local governments petitioning to overturn the ban were joined by the measure's sponsors and Attorney General Jerry Brown. The justices directed Brown and lawyers for the 'Yes on 8 campaign' to submit arguments by December 19.

The court case thus pits two fundamental concepts of US democracy against one another - first, gay marriage advocates saying the proposition would open the doors to systematic repression of minorities, and second, opponents saying courts must recognize the will of the people under separation of powers doctrine.

In a statement, San Francisco Mayor Gavin Newsom, comparing the fight for gay marriage to the 1960s civil rights battle against majority-tolerated segregation, said: "I am optimistic that the Supreme Court will affirm that separate is not equal."