Opponents of Michigan's wolf hunt are challenging a law that says people who collect petition signatures must be state residents.
They filed a lawsuit Sunday in Detroit Federal Court, saying the law should be thrown out as a violation of the First Amendment. They're asking Judge Robert Cleland to immediately suspend the requirement while the case moves through court.
Wolf hunt critics want to overturn a law that led to the first hunt in the Upper Peninsula in November. They need about 162,000 signatures to get the question on the fall ballot, but can't bring allies in from outside Michigan to collect names.
The Michigan branch of the American Civil Liberties Union says similar residency restrictions have been struck down in other states.