Hazleton, Pa. ? Hispanic activists and the ACLU sued Hazleton on Tuesday over one of the toughest crackdowns on illegal immigrants by a U.S. city.

Hazleton, a city of about 31,000 people 80 miles from Philadelphia, voted last month to fine landlords $1,000 for renting to illegal immigrants, deny business permits to companies that give them jobs, and make English the city’s official language.

The lawsuit contends that the Constitution gives the federal government exclusive power to regulate immigration and that the city’s ordinance is discriminatory and unworkable.

In response, Hazleton Mayor Louis Barletta pledged to take the fight to the nation’s highest court. In the meantime, he began soliciting donations for the legal battle. “To paraphrase an American patriot, we have not yet begun to fight,” the mayor said.