Advocates for legalized marijuana submitted a petition Monday in South Portland that’s expected to force a November referendum on support for legalizing recreational use by adults.

Citizens for a Safer Maine, which is also pushing for marijuana legalization votes in York and Lewiston, handed in 1,521 signatures to South Portland city officials.

The group must submit 959 valid signatures of registered city voters to qualify for the November ballot. The city clerk has 20 days to certify the petition.

The campaign is being led by David Boyer, Maine political director of the Marijuana Policy Project, which helped pass a ballot initiative last year in Portland that declared recreational marijuana use in the city legal for adults 21 and older. While the activists are pushing to declare the activity legal in the various municipalities, the votes will have more political value than practical effect because marijuana use remains illegal under state and federal law.

“Our goal is to get people talking about marijuana and the benefits of ending prohibition,” Boyer said in a prepared statement. “Marijuana is far less harmful than alcohol for the consumer and for society. It should be treated in that way, and that entails no longer punishing adults who choose to use it responsibly.”

The petition calls for allowing people 21 and older to carry an ounce of marijuana without penalty. This is less than the Portland ordinance, which allows people to carry 2.5 ounces.

“Right now we don’t know who’s buying marijuana or who is selling it,” Boyer said at a Monday afternoon news conference outside South Portland City Hall.

“There’s harsh penalties for liquor stores that sell to minors. We can revoke their licenses if they sell to minors,” Boyer said. “We just don’t have that oversight with marijuana.”

After the group began collecting signatures, the South Portland City Council passed a non-binding resolution opposing the legalization campaign.

South Portland Mayor Jerry Jalbert has publicly come out against a referendum and said it isn’t a good way to engage public opinion.

“We have no legal authority at the municipal level,” Jalbert said. “This is really more of a ploy where if it were to pass they could bring it to the state Legislature. This is a non-binding item. It’s not a real change.”

Janet Vangeli, a crime analyst with the South Portland police, said there have been 98 marijuana citations given to people 21 and older in the last year and 10 citations given to juveniles, which is average for the last three years. The numbers include marijuana citations issued during unrelated arrests.

Annie Sarbanis, a South Portland mother and professional photographer, spoke in support of the referendum Monday. She said that while she does not consume marijuana, she has friends and colleagues who do.

“I’ve seen its health benefits,” Sarbanis said. “It’s time to take a good look at the law.”

Also at the news conference was Democratic U.S. Senate candidate Shenna Bellows, who advocated for the local petition as well as the statewide and federal legalization of marijuana. Bellows also announced her support for the Redeem Act, a bipartisan bill by Sens. Cory Booker, D-N.J., and Rand Paul, R-Ky., that would expunge juveniles’ nonviolent criminal records.

“The war on drugs has failed,” Bellows said. “I’m proud to stand with Republicans and Democrats alike in backing drug law reform and criminal justice measures that will strengthen our communities.”

A spokesman for the re-election campaign for U.S. Sen. Susan Collins said he had no comment on the local referendum. Collins has declined in the past to take a side on the issue of statewide legalization.

Scott Gagnon, executive director of Smart Approaches to Marijuana Maine, issued a statement Monday opposing the legalization effort, saying the state must first address the public health issues posed by legal drugs, such as alcohol and tobacco, before adding marijuana.

“Legal drugs … have many more youth users compared to illicit marijuana,” Gagnon said. “Now is not the time to add to the problems.”

Citizens for a Safer Maine submitted a similar petition in York, where selectmen last week voted to hold a public hearing on that town’s petition on July 28. The selectmen would then vote to put the petition out for a town-wide vote in November.

Boyer has said the group continues to collect signatures in Lewiston, where it will need more than 859 signatures to qualify for a referendum vote.

“It makes sense to end marijuana prohibition just like it made sense to end alcohol prohibition,” Boyer said.

Staff Writer Gillian Graham contributed to this report.