In a split decision the California Supreme Court has voted to up-hold Proposition 8, a voter-approved initiative, banning same-sex marriages in the state.

The 6-1 decision written by Chief Justice Ron George rejected an argument by gay rights activists that the ban revised the California constitution’s equal protection clause to such a dramatic degree that it first needed the Legislature’s approval.

The court said the people have a right, through the ballot box, to change their constitution.

“In a sense, petitioners’ and the attorney general’s complaint is that it is just too easy to amend the California constitution through the initiative process. But it is not a proper function of this court to curtail that process; we are constitutionally bound to uphold it.

“After comparing this initiative measure to the many other constitutional changes that have been reviewed and evaluated in numerous prior decisions of this court, we conclude Proposition 8 constitutes a constitutional amendment rather than a constitutional revision,” the ruling said.

The court did though rule to allow the estimated 18,000 gay couples who married in California before the law took effect to stay wed.

The announcement of the decision set off an outcry among a sea of demonstrators who had gathered in front of the San Francisco courthouse awaiting the ruling.

Holding signs and many waving rainbow flags, protesters chanted “shame on you”, while many people also held hands in a chain around an intersection in an act of protest.

Gay rights activists immediately promised to resume their fight, saying they would go back to voters as early as next year in a bid to repeal Proposition 8, while marches have been scheduled for throughout California and in several other states this evening to protest the court’s ruling.