California’s plastic bag ban has been signed into law, but opponents have pledged to fight on.

The nation’s first state-level ban on single-use checkout bags was signed into law on Sept. 30 by California Gov. Jerry Brown, who afterward praised the measure as a sign of things to come.

“This bill is a step in the right direction – it reduces the torrent of plastic polluting our beaches, parks and even the vast ocean itself,” Brown said in a press release. “We’re the first to ban these bags, and we won’t be the last.”

That announcement, however, was countered by a fierce proclamation from the ban’s primary opponent, the SPI: The Plastics Industry Trade Association-funded American Progressive Bag Alliance (APBA). After lobbying aggressively but unsuccessfully in the weeks and months leading up to the bill’s passage through the California legislature, APBA has now set its sights on a referendum.

“We have taken the necessary steps to gather signatures and qualify a referendum to repeal SB 270 on the November 2016 ballot,” an APBA statement reads. “Since state lawmakers failed their constituents by approving this terrible bill, we will take the question directly to the public and have great faith they will repeal it at the ballot box.”

APBA has been a vocal critic of bag ban ordinances throughout the country, attacking the overall effort as misguided. The group characterized California’s law as “a backroom deal between the grocers and union bosses to scam California consumers out of billions of dollars without providing any public benefit.”

The website of California Secretary of State Debra Brown confirms that a referendum is indeed possible on the measure, although APBA will have to move quickly.

“A proponent has only 90 days from the date of the enactment of a bill … to request and receive a title and summary from the Attorney General … print petitions, gather the required number of valid signatures, and file the petitions with the county elections officials,” the explanation reads.

APBA will have to gain a little more than 500,000 valid signatures to get the issue in front of voters.

In addition to banning single-use plastic bags, the California law requires a minimum 10 cent charge on paper, compostable and reusable bags.