A group called the Common Sense Patriots is suing the city of Coldwater over a ban on all signs in a public park.
The group says Coldwater's policy at Four Corners Park violates the First Amendment. It was adopted in a 5-4 council vote last fall.
The Common Sense Patriots is part of the national tea party movement. It holds events at Four Corners Park, sometimes drawing more than 200 people. The group's signs include one that says, "Born Free ... Taxed to Death."
The federal lawsuit says Coldwater's ban was approved months after the group had a hard time getting approval to display a tea party banner last summer. A message seeking comment was left with the city attorney.