121Sustainability in Public Contracts

Abstract This article examines the role of public contracts as instruments for advancing sustainability and climate objectives within EU public procurement law. While Green Public Procurement has long been recognised as lawful, a significant rise in sustainability requirements and practices for integrating green considerations into procurement procedures and contract performance raises a number of legal questions. In parallel, the reliance on public contracts to advance sustainability objectives intensifies the interface between procurement law and contract law. Focusing on the public contract, the article analyses how sustainability may be incorporated and enforced, including with attention to the requirement that such conditions be linked to the subject matter of the contract. It further explores the substantial modification regime, and the implications of emerging national practice treating inadequate contractual enforcement as equivalent to unlawful contract modification. The article argues that while procurement law and contract law can mutually reinforce sustainability objectives, their interaction also generates new tensions that call for careful doctrinal calibration.