Dan Hayes is accusing Denver of ignoring the will of the voters.

The sponsor of a voter-approved ballot measure "requiring" Denver police to impound the vehicles of unlicensed drivers reacted angrily Thursday to a legal analysis of Initiative 100 from the city attorney's office, which says that police will continue to have "discretionary authority."

"It's a disaster, and we'll have more of these Hernandezes driving off the road and killing three or four people at a time," Hayes said.

The analysis maintains the initiative didn't change the "basic principle" that police have discretion to order impoundment.

"I don't know that that's what the proponents intended, but . . . the discretion remains with the officers," city spokeswoman Revekka Balancier said.

The analysis was "complicated" because the ballot language, which Hayes wrote, doesn't match the language of the ordinance, according to a statement from the city attorney.

"In general, the city attorney has advised that the actual language of the ordinance, not the language of the ballot question, controls the interpretation of the law now that it has been adopted by the voters," it says.

The Aug. 12 ballot question asked: "Shall the voters for the City and County of Denver adopt an ordinance requiring that a motor vehicle operated by an unlicensed driver be impounded?"

Hayes said he plans to challenge the city's analysis.

The city attorney's statement says Denver is ironing out the details for implementation. But it says police will need to consult with federal immigration officials before vehicles can be impounded based on immigration status.

"The text of I-100 authorizes the impoundment of vehicles driven by suspected illegal immigrants," the statement says. "The city attorney has advised DPD officers to make arrangements with federal immigration officials to coordinate any determination of a driver's immigration status with ICE before seizing and impounding any vehicle."