Denver police would have to impound the vehicles of unlicensed drivers under a proposed ballot measure that a sponsor said is aimed at driving illegal immigrants out of Colorado.

Los Angeles police slammed the brakes on a similar practice after the city attorney's office determined it may be unconstitutional to automatically impound vehicles, said Kevin R. Johnson, a law professor at the University of California at Davis School of Law.

"They changed the policy to try to avoid any potential lawsuits and potential liabilities," he said.

But supporters of the measure, which they hope to get on the city ballot in August 2008, were undeterred.

"If we want to have any kind of future around here at all, something has to be done," Daniel Hayes, treasurer of a committee behind the proposal, said Tuesday. "They don't belong here. They need to go home and work their problems out there."

The proposed measure, which city officials will discuss Thursday, also calls for the owner to post a $2,500 bond to get the vehicle back. If another unlicensed driver operates the vehicle within a year, the bond is lost.

Hayes, a Jefferson County resident, said the committee decided to focus on Denver first and expand the proposed policy later.

"Denver is a magnet (for illegal immigrants) and it creates a problem for the entire metro area," Hayes said. "As long as they got a place where they're safe, where they can go, they can drive, they can live, then they're going to be a problem everywhere."

Denver Sheriff's Capt. Frank Gale said the city's vehicle impound lot handles about 20,000 automobiles annually.

"A lot of cars get impounded now that belong to people that are not documented because they don't have proper proof of ownership," Gale said. "They don't have a driver's license. They don't have a registration."

A police spokesman said officers don't always impound vehicles operated by unlicensed drivers. If a licensed driver can pick it up, the officer may decide not to tow it.

chacond@RockyMountainNews.com or 303-954-5099