The PLUS Act of 2023 amends federal labor laws to restrict labor unions' ability to engage in work slowdowns and block modernization efforts at U.S. ports. The bill specifically prohibits maritime employees and labor organizations from intentionally reducing productivity or efficiency during port operations and from impeding port modernization projects, even when collective bargaining agreements are in effect. The legislation affects port workers, labor unions, shipping companies, and businesses reliant on maritime commerce. Companies harmed by violations can recover double damages plus attorney and expert witness fees, and workers cannot waive their right to pursue these monetary claims through grievance procedures or other contract provisions. The bill addresses concerns about supply chain disruptions caused by labor actions at ports and aims to maintain U.S. competitiveness in global trade.