SEATTLE — A group of public health experts and others are challenging a proposed King County initiative that would ban safe injection sites for drug users.

A lawsuit filed Monday comes days after county elections officials verified signatures for Initiative 27, which would ban supervised sites where people can use heroin and other drugs.

Protect Public Health’s lawsuit seeks to invalidate the measure, arguing that public health policy is outside the scope of the initiative process.

A spokesman for I-27 called the lawsuit another attempt to disenfranchise voters who want to have a say on the radical proposal.

The Metropolitan King County Council can pass the initiative as written or send it to voters, likely in February. An elections official says Aug. 1 was the administrative deadline for the November ballot.

Council budget chair, Dave Upthegrove, says he’ll oppose county funding for safe injection sites until the public has a chance to vote on I-27.