Proposal backed by Silicon Valley’s Sean Parker would allow for the retail sale to adults 21 and older, potentially bringing in more than $1bn a year in tax revenue

A plan backed by Silicon Valley billionaire Sean Parker to legalize recreational use of marijuana in California is on the path to the November ballot, potentially bringing more than $1bn a year in tax revenue, according to legislative analysts.

The proposal, which would allow for the retail sale of marijuana to adults aged 21 and older, is one of the most highly anticipated initiatives, in no small part because California is the country’s largest economy and the eighth largest in the world.

But some industry insiders are unhappy with the proposal – which is backed by Parker, the founder of Napster, and Justin Hartfield, the founder of WeedMaps – and are withholding support.

“This skews towards big marijuana,” said Hezekiah Allen, executive director of the California Growers Association, an industry trade and lobbying group.

The state’s attorney general cleared the Adult Use of Marijuana Act (AUMA) on Wednesday, allowing the campaign for the measure to begin. The first hurdle will be gathering 365,880 signatures to qualify for this year’s general election – an effort that will start “in a handful of days”, according to AUMA spokesman Jason Kinney. Signature gathering could cost as much as $2m, with the overall campaign reaching $10m, according to industry sources.

Campaign organizers have formed a political action committee called Californians to Control, Regulate and Tax Adult Use of Marijuana while Protecting Children, which says it has collected $1.25m including from Parker; Hartfield; Drug Policy Action, the PAC of the Drug Policy Alliance; and the Marijuana Policy Project of California. Parker has contributed $250,000 from his foundation effort and another $250,000 as a matching contribution through a Pac, according to filings with the California secretary of state. Hartfield’s WeedMaps also donated $250,000 through its own Pac, and a Pac associated with the heirs of Progressive Insurance founder Peter Lewis contributed $250,000.

Allen and some growers are concerned the AUMA would favor corporate interests over the small farmers who currently dominate the industry in the state while other stakeholders worry the measure doesn’t go far enough to decriminalize marijuana.

“The Parker initiative does not respect the provisions that were developed in the legislature that protect a fair marketplace,” said Allen, referring to the framework created by state lawmakers last year to regulate medical marijuana market – which had functioned largely without oversight for nearly 20 years. Allen said his group was concerned there were not enough limitations against “vertical integration”, or allowing businesses to take part in multiple aspects of cultivation, distribution, and retail sales at once.

For that reason, he says, his organization is remaining officially neutral on the proposal despite “pressure to fall into line”, although he said he would continue to talk to AUMA organizers.

Dale Sky Jones, chair of Coalition for Cannabis Policy Reform and its offshoot, Reform CA, said her organization was taking a similar position. Reform CA had previously cleared its own legalization ballot measure last year but voted in December to hold off gathering signatures based on the momentum behind the Parker proposal and to avoid “mutual destruction” with competing measures, she said.

Facebook Twitter Pinterest The proposal is backed by Sean Parker, the founder of Napster. Photograph: Gonzalo Fuentes/Reuters/Corbis

“We are not going to oppose and we are not going to compete,” she said. “We are simply standing down.”

Despite that, Jones said she still has concerns that the AUMA does not go far enough with legalization and does not adequately address social justice issues that her group considers paramount in the debate – such as shielding parents involved in cannabis activities from legal issues with child protective services.

“It’s not true legalization,” she said of AUMA. “It’s just softer prohibition.”

California’s legalization efforts have long been plagued by dissenting opinions and lack of unity – divisions that contributed to a 2010 failed attempt at legalization. Reform CA was one of the first efforts to create some cohesion for stakeholders, but Kinney said that AUMA has also “done everything we can to build the broadest consensus possible”, including amending the plan based on concerns raised after the initial proposal was released.

Those changes helped gain the backing of some groups that were undecided, including the NAACP. Alice Huffman, president of the California NAACP and a member of Reform CA, said she “had issues that I wanted taken care of concerning the African American community”. An earlier version of the Parker plan included restrictions on licenses in neighborhoods with higher crime rates and did not put tax dollars directly into the hands of community organizations – both areas that she felt negatively impacted African American and minority communities.

Huffman said AUMA representatives made fixes in its language to address those disputes, winning her support. “I don’t think they were perfect in doing it, but I don’t think there are enough problems with it that we should be out opposing it,” she said, calling legalization a “civil rights issue”.

But Jones says the outstanding divisions within the legalization movement could keep many stakeholders from volunteering their time towards the initiative – or even voting in its favor.

“I have spent my entire life looking forward to the end of prohibition, and I cannot tell you what I will do at the ballot box,” said Allen, echoing that sentiment.

Jones added that lukewarm reception from stakeholders like her may leave the AUMA campaign to depend less on volunteers and more on paid media to get its message out.

“They are going to come in and drop their advertising bombs and go out again,” she predicts. “It’s not enough to get anyone impassioned … They are not going to put aside their lives, their time, their money to fight for something that isn’t going to accomplish what they want it to accomplish.”

Kinney said the campaign would likely hold off on any major advertising until after the June primary but has “an enthusiastic group ready to go … and ultimately if you support a legal, open and controlled and regulated system, then this is the measure you are going to support”.

Huffman backed that position. She said that the NAACP would “actively support” AUMA, including direct mailings to 300,000 African American voters.

“I’ll do whatever it takes to succeed,” she said. “Parker has got the money … it would be foolish not to get this thing passed while the environment is right.”