This publication is available on open access at: https://brill.com/view/journals/ilrc/7/3/article-p257_257.xml. An ad hoc Panel of Experts has determined for the first time that a free trade partner of the European Union violated sustainable development obligations under the new generation of free trade agreements (FTAs). The Republic of Korea (Korea) was the EU’s first trading partner to ratify such an agreement. After a European Commission non-paper in 2018 promised “more assertive” use of the soft dispute mechanism for “trade and sustainable development” (TSD) issues in free trade agreements, the EU filed formal proceedings against Korea. The Panel’s report is a milestone decision that will likely serve as a precedent for future ad hoc panels. The Panel—consisting of Laurence Boisson de Chazournes, Jaemin Lee, and Jill Murray as chairperson—had considered two EU claims involving TSD issues in the EU-Korea FTA. The claims related to the first and the last sentences of Article 13.4.3 of that agreement. The first sentence explains that the parties commit to respecting, promoting, and realizing the principles concerning the fundamental labor rights in their laws and practices in accordance with the obligations deriving from ILO membership. The EU asserted that Korea had violated this provision. Articles 2(1), 2(4)(d), 23(1) and 12(1)–(3), in conjunction with Articles 2(4) and 10 of Korea’s Trade Union and Labor Relations Adjustment Act (TULRAA) of 1997, the EU complained, would not be in accordance with freedom of association. The last sentence of Article 13.4.3 of the EU-Korea FTA stipulates that the parties are required to “make continued and sustained efforts towards ratifying the fundamental ILO Conventions.” The EU alleged that such efforts had not been made regarding four relevant fundamental conventions: Nos. 29, 97, 98, and 105.