A second group launched its own effort Tuesday to legalize marijuana for recreational use in Arizona, potentially putting both campaigns in jeopardy.

The new group, known as the Campaign to Legalize and Regulate Marijuana, filed the necessary paperwork Tuesday to start gathering signatures for a proposal to let adults use the drug for recreational use. Backers need 150,642 valid signatures by July 7, 2016 to qualify for the general election ballot that year.

Only thing is, the move comes exactly a month after the Campaign to Regulate Marijuana Like Alcohol began its own petition drive to put a similar but not exactly duplicate initiative on the 2016 ballot. It also needs the same number of signatures.

And that’s where the first problem arises.

Individuals asked to sign paperwork petition to let people smoke and otherwise consumer marijuana may respond that they already have penned their name to a petition. But they may not know whether it was the same petition or the competing measure.

If what they sign is in fact the same initiative, then their duplicate signature becomes a problem for organizers.

That’s because counties check only 5 percent of petitions turned in and then extrapolate what they have found. So each bad or disqualified signature translates out to reducing the total gathered by 20.

Conversely, if they decline to sign a second petition, that potentially denies organizers of a signature they need.

And even if both manage to qualify for the ballot, that creates another level of confusion for voters who may be unaware they can vote for both. That, in turn, raises the potential of splitting the pro-marijuana vote, leaving each measure short of the majority.

That’s exactly what happened in 1990 when there were two measures on the Arizona ballot to create a holiday to honor slain civil rights leader Martin Luther King Jr. It took two more years for supporters to unite behind a single measure and get it approved.

“There is definitely the danger of confusion,” said Carlos Alfaro. He is the Arizona political director of the Marijuana Policy Project, the group pushing the initiative filed last month.

It also is the same organization that got voters to narrowly approve a 2010 measure allowing those with certain medical conditions and a doctor’s recommendation to obtain and use marijuana.

But Alfaro said he believes that most of the businesses that have an interest in the issue, specifically the existing medical marijuana retailers, already have lined up behind his measure. And he said the signature-gathering process already has started.

Calls and email messages to organizers of the newly filed initiative were not immediately returned.

There are common threads between the two measures.

For example, both permit adults to possess up to an ounce of marijuana at any one time. Both also require the Department of Health Services to license a certain number of dispensaries. And both also impose a 15 percent tax, with the proceeds going to public education and health.

They both also specify that any adult caught with more than an ounce of weed but less than 2 1/2 ounces can be slapped with a $300 fine and community service.

But the newer measure says having up to eight ounces is only a Class 3 misdemeanor, with a $500 fine and the possibility of 30 days in jail. The earlier one keeps the law above 2 1/2 ounces the way it is, with possession being a felony.

Alfaro said that language mirrors what was passed in Colorado and Alaska.

“We don’t want it to seem as irresponsible,” he said. “We want to regulate responsible adult use, a limited amount of marijuana.”