A proposal to legalize marijuana in Arizona is on track to qualify for the November ballot as the state joins a growing movement looking to loosen pot laws around the country in the November elections.

A spokesman for Arizona's leading recreational marijuana initiative says the measure has already collected about 140,000 of the 150,000 signatures necessary to get on the ballot. The campaign intends to collect more to account for disqualified signatures. Backers have until July to collect the remaining signatures.

An unusual alliance has formed to oppose the measure. Maricopa County Attorney Bill Montgomery and backers of a separate pot measure seeking to qualify for the ballot have come out against the plan.

Arizona is one of least nine states that have pending recreational marijuana initiatives this year.