Oregon’s powerful teachers’ union is warning that a proposed drug decriminalization ballot measure could take millions of dollars from the state’s public schools.

The Oregon Education Association says it isn’t taking a position at this point on the initiative, which would decriminalize personal possession of a wide range of illegal drugs, including heroin and methamphetamine.

The union says the measure could reduce funding for schools by around $37 million a year.  That’s because it would divert much of the taxes from legal marijuana sales from schools and other services to beefed-up drug treatment programs.

While this is a small portion of the more than $6 billion a year spent on schools, it could have a noticeable effect on local budgets.

The union on Friday filed comments with the secretary of state complaining that the proposed ballot language describing the initiative “provides virtually no explanation of how the initiative is funded and the impact on school funding.”

In its comments, the union added:

“Who would not want to fund more addiction recovery programs in the abstract? But if money for those services is coming from education and other programs, the choice is less clear.”

Peter Zuckerman, a spokesman for the decriminalization measure, said in a statement that the lack of drug treatment has had a “devastating impact on the state,” including for schools and student families.

He said he looked forward to “continuing the conversation with” the union on the measure, which is now designated as Initiative Petition 44.

The initiative is backed by the Drug Policy Alliance, a New York-based group that has long been in the forefront of efforts around the country to legalize marijuana. The group, which has received major support from billionaire investor George Soros, has long argued that prosecuting illegal drug users is counterproductive.

The group hasn’t decided yet whether it will support launching a signature-gathering effort to qualify for the November 2020 ballot. For now, backers are seeing what kind of language it gets for a ballot title. That language can often play an important role in determining how voters react to a measure.

A statement from the union’s vice-president, Reed Scott-Schwalbach, said in a statement that “educators believe that treatment is a critical component of overcoming addiction,” but she said the union isn’t ready to take a stand on the measure.

“We filed comments to clarify that the funds this measure affects are currently partially dedicated to Oregon school funding,” Scott-Schwalbach said, “and we believe that information should be reflected in the materials about this measure.”

Backers of the measure filed their own comments on a draft ballot title for IP 44. Instead of focusing on drug decriminalization, they said it should first emphasize how the measure would expand access to drug treatment.