Iowa Code § 732.3

It shall be unlawful for any labor union, group, association or organization, or the officers, representatives, agents or members thereof, to cause a stoppage or slowdown of the work or a part of the work of an employer because of a dispute between labor unions, groups, associations or organizations, or the officers, representatives, agents or members thereof, with respect to jurisdiction over, or the right to do the work or a part of the work of such employer.