DENVER | Big changes could be coming to public schools in Colorado, assuming Colorado voters want to raise the income tax to pay for them.

Democratic Gov. John Hickenlooper plans to sign the overhaul into law on Tuesday. The changes aim to reverse years of underfunded public schools and pay for statewide full-day kindergarten.

But the changes come with a big question mark. They take effect only if Colorado voters approve about $1 billion a year in higher income taxes.

The tax question will be petitioned onto ballots by advocacy groups, so it’s too soon to say what exactly the proposed tax would be. Hickenlooper has said he’ll push for the higher tax because schools need the upgrades.