PHOENIX (AP) — A ballot initiative to mandate the increased use of renewable energy will be put to voters as Proposition 127.

Secretary of State Michele Reagan said Thursday that signatures filed by the Clean Energy for a Healthy Arizona Initiative has qualified for the ballot after a review of its petitions.

Reagan's office said the review showed that the campaign handed in an estimated 328,908 valid signatures, more than 100,000 than were needed to qualify for the ballot.

But the initiative is still being challenged with a lawsuit that seeks to knock it off the ballot. A trial is scheduled for next week.

The Clean Energy for a Healthy Arizona proposal seeks to amend the state constitution to require half the state's energy come from renewable sources by 2030.