(CNN) It looks like Californians won't be voting on whether to split their state into three.

The California Supreme Court shot down the controversial initiative from appearing on the November ballot in a unanimous decision, writing that "significant questions have been raised regarding the proposition's validity."

Proposition 9 would've asked voters whether California should separate into three states: California, Northern California and Southern California. It would've been subject to approval by US Congress. The initiative had gained enough signatures in June to qualify for the ballot on November 6.

"We conclude that the potential harm in permitting the measure to remain on the ballot outweighs the potential harm in delaying the proposition to a future election," the justices wrote.

The court directed the Secretary of State of California, Alex Padilla to refrain placing Proposition 9 on the upcoming ballot.

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