DENVER, Colo. -- Opponents of a newly approved measure allowing Denver police to seize cars driven by illegal immigrants expect it to be challenged in court.

Voters approved Initiative 100 on Tuesday by 54 percent to 46 percent.

Lindsey Hodel of the Committee to Defeat 100 said Wednesday that her group expects someone to file a court challenge but has not decided whether it will do so.

Denver City Attorney David Fine issued the following statement on Wednesday regarding the passage of Initiative 100:

“We are closely examining Initiative 100. As we stated before it passed, the City Attorney’s Office has concerns about its constitutionality. Given those concerns, we will carefully analyze the initiative over the next several days and advise City officials regarding implementation and enforcement.”

The measure allows police to impound cars driven by illegal immigrants, or by people who are "reasonably suspected" of being illegal immigrants.

It also requires police to seize cars driven by unlicensed drivers. State law bars illegal immigrants from getting licenses.

Supporters argue it will get unlicensed drivers off the street. Opponents said it will hurt working families and will be expensive and difficult to enforce.