California ? The California Supreme Court will rule Tuesday on the validity of a voter-approved ban on same-sex marriage, a decision that will end months of speculation over whether gay couples can resume marrying in the state.

The high court announced the pending opinion on its Web site Friday morning.

Justices are considering a series of lawsuits seeking to overturn a constitutional amendment approved by voters in November that overruled a 4-3 court decision that briefly legalized same-sex unions. The suits claim Proposition 8 was put on the ballot improperly.

The court also will decide whether to uphold the marriages of an estimated 18,000 gay couples who wed before Proposition 8 passed. The election came after a contentious $83 million campaign that made it the most expensive ballot measure on a social issue in the nation’s history.

Gay rights advocates have scheduled marches throughout California and in several other states for Tuesday evening. Organizers say the gatherings will be celebratory if the court rules in their favor and angry if Proposition 8 is upheld.