Union members and others protested a Milwaukee area Costco, calling for a boycott of a pizza maker.
They accuse Milwaukee-based Palermo's Pizza of unfair labor practices and want Costco to pull the pizzas from their shelves.
WTMJ-TV reported that dozens protested in front of the Grafton Costco Saturday. It was organized by the immigrant rights group, Voces de la Frontera.
Workers, many of whom are Hispanic, have been on strike since June 1. They said the company has tried to stop them from forming a union but Palermo's management denies that. Palermo's said Chief Executive Officer Giacomo Fallucca and AFL-CIO president Richard Trumka are trying to set a meeting.
Union members were expected to hold protests at 25 Costco stores around the country.