<![CDATA[Environmental criminal law enforcement in Indonesia underwent reconfiguration following the enactment of the Undang-Undang Cipta Kerja, Undang-Undang Nomor 1 Tahun 2023 tentang Kitab Undang-Undang Hukum Pidana (KUHP Nasional), and Undang-Undang Nomor 1 Tahun 2026 tentang Penyesuaian Pidana. These changes have raised questions regarding the position of the ultimum remedium principle in determining the use of criminal law against environmental offenses and in corporate criminal liability. This study aims to analyze the construction of environmental offenses following the amendments introduced through the Undang-Undang Cipta Kerja, judicial practices in applying the principles of ultimum remedium and primum remedium, and the repositioning of the ultimum remedium principle following the enactment of the KUHP Nasional, particularly in the context of corporate criminal liability. This study employed a normative legal method using statutory, conceptual, and case approaches through an analysis of relevant legislation and court decisions. The findings indicate that, first, ultimum remedium is not formulated as a general prerequisite for imposing criminal sanctions and is explicitly attached only to Article 100(2) of the UUPPLH, whereas the Undang-Undang Cipta Kerja introduced a structural ultimum remedium model for licensing violations through Articles 82A–82C and Article 109. Second, judicial practice demonstrates inconsistent application because it depends on judicial interpretation and interinstitutional coordination. Third, the KUHP Nasional provides sentencing objectives and guidelines, provisions on corporate liability under Articles 45–50, and additional penalties and measures for corporations under Articles 118–123, which are better able to accommodate proportionality considerations. Based on these findings, the ultimum remedium principle needs to be repositioned from a determinant of criminalization to a tiered guideline for formulating legal norms, exercising prosecutorial discretion, and imposing criminal sanctions, accompanied by selection criteria based on the una via principle and strengthened institutional coordination. This repositioning offers a conceptual framework for more proportionate, consistent, and accountable environmental criminal law enforcement, particularly in addressing corporate criminal liability.]]>
