The group behind a ballot measure aiming to cap the state’s income tax rate at 4.4% and counter the push for a graduated system has submitted 190,000 voter signatures to election officials for review.

Backed by Advance Colorado, Initiative No. 232 would cap Colorado’s individual and corporate income tax rate at 4.4%. That rate has been in place since 2022.

“This is a clear counter to the far left’s attempt to hike taxes in Colorado, price people out of the state we love, and drive business out. We’ll always fight to protect TABOR and keep our taxes low,” Michael Fields, executive director of Advance Colorado, said.

Colorado is one of 15 states with a flat income tax rate, meaning all taxpayers pay the same percentage of their income, regardless of how much they make.

The alternative is a graduated or progressive tax rate. A coalition of progressive groups is pushing to put such a proposal on the November ballot.

Initiative No. 195, backed by the Denver-based think tank Bell Policy Center and a coalition known as Protect Colorado’s Future, would establish a graduated income tax, in which individuals and businesses would be taxed differently based on their earnings.

For example, those who make over $1 million a year would see an increase from the current flat income tax rate of 4.4% to 8.41%, while those earning under $25,000 would see a reduction to 3.71%.

The federal government uses a graduated income tax rate, as do several states, including Minnesota, Wisconsin, California and Alabama.

The graduated tax proposal is anticipated to increase the tax base by $2 billion to $4 billion, depending on which proposal ultimately ends up on the ballot. The new revenue would be used for K-12 education, health care and early child care and education, according to the proponents.

Kathy White, the executive director at Colorado Fiscal Institute, which supports the measure, argued that Colorado’s working families “shouldn’t have to pick up the tab so the wealthiest get a $71,000-a-year gift from Congress — especially when TABOR has already tied our hands for decades.”

Advance Colorado, on the other hand, argues that a graduated income tax will “chase revenue out of the state” and result in lost revenue, not more.

“If you go and double taxes for businesses or individuals that are higher income earners, they’re going to leave the state and go somewhere else,” he said.

Protect Colorado’s Future has not yet submitted its signatures to the Secretary of State’s Office, but it has until Aug. 3 to do so. To qualify for the ballot, initiatives must receive just over 124,000 valid signatures.

If both initiatives are approved, the one with the higher vote total would take effect. That means a victory for Initiative 195 would move Colorado to a graduated income tax system, while a win for Initiative 232 would allow income tax cuts but prohibit increases.

“The last thing Colorado needs right now is a tax hike,” Advance Colorado’s executive director Michael Fields said in a social media post on Thursday. “Approving this measure would make sure that doesn’t happen.”