When the UN Guiding Principles on Business and Human Rights (UNGPs) were unanimously endorsed by the UN Human Rights Council in 2011, they marked a turning point in global governance. The UNGPs defined how States and businesses share responsibility for preventing and addressing human rights harms. Built on three pillars, the State duty to protect, the corporate responsibility to respect, and the shared responsibility of States and businesses to ensure access to effective remedy, the UNGPs brought long-needed coherence to an area previously dominated by fragmented practices and voluntary commitments.
At their core lies Human Rights Due Diligence (HRDD): the process by which companies identify, prevent, mitigate and account for adverse human-rights impacts across their operations and value chains. Yet, despite establishing an authoritative global standard, the UNGPs remain soft law, guiding rather than binding. And still, within just over a decade, these “soft” norms have begun to influence hard law.
From Aspirational Soft Law (lex ferenda) to Binding Domestic Law (lex lata)
Historically, international human rights obligations were vertical, binding only on States. The rise of multinational corporations and global supply chains exposed the limits of this model. States alone could not regulate transboundary corporate conduct and victims of corporate abuse were often left without remedy.
In this context, the UNGPs filled a governance vacuum. Although they impose no direct legal duties, their influence on legislation and corporate practice has been profound.
Across both civil- and common-law systems, States have begun to translate the UNGPs’ normative expectations into binding legislation, as illustrated by recent developments in:
- France’s Duty of Vigilance Law (2017) requires large companies to implement due-diligence plans across global operations, referencing the UNGPs as a global benchmark.
- Germany’s Supply Chain Due Diligence Act (LkSG, 2023) similarly grounds its obligations in the HRDD framework, explicitly citing the UNGPs in its explanatory report.
- Norway’s Transparency Act (Åpenhetsloven, 2022) explicitly builds on the UNGPs and requires larger companies to conduct ongoing human-rights and decent-working-conditions due diligence across their operations and supply chains, as well as granting the public a right to request information about these assessments.
- The EU’s Corporate Sustainability Due Diligence Directive (CSDDD), which entered into force on 25 July 2024, requires Member States to transpose its provisions into national law by 26 July 2027. It builds directly on the UNGPs, transforming voluntary expectations into enforceable duties for large companies across the European Union.
- In the United Kingdom, the National Action Plans (2013, 2016) and the updated Modern Slavery Act 2015 guidance (published in March 2025) explicitly reference the UNGPs as the framework for modern-slavery due diligence.
- Complementing these statutory frameworks, a major development jointly released by the UK, Canadian, and Australian governments, the Optional Cross-Jurisdictional Reporting Template, enables organisations to prepare a single transparency report addressing supply-chain obligations under the UK Modern Slavery Act 2015, Australia’s Modern Slavery Act 2018 and Canada’s Fighting Against Forced Labour and Child Labour in Supply Chains Act (2023). This harmonised template reduces administrative burden, aligns key definitions and promotes consistency across jurisdictions.
Together, these developments mark a clear normative shift from corporate social responsibility (long grounded in voluntary norms) to emerging legal duties, as States increasingly codify due-diligence obligations in binding law. The once-voluntary HRDD standard is now embedded in multiple legal systems, signalling an accelerating process of juridification (the gradual codification of normative expectations into enforceable legal frameworks).
At the international level, the diffusion of HRDD obligations through national laws signals emerging State practice (usus). However, without a shared belief that such conduct is legally required (opinio juris), the UNGPs cannot yet be considered customary international law in their entirety. They operate instead as material sources that influence the formation of binding norms, a hybrid zone where soft law informs hard law. Critically, the UNGPs operationalise pre-existing hard law: the prohibitions on the most severe human rights abuses (such as slavery, torture and the worst forms of child labour) are already considered peremptory norms of international law (jus cogens). The HRDD process, therefore, provides the globally accepted standard of care for businesses to prevent breaches of these fundamental, non-derogable legal duties.
The Road Ahead: Hybrid or Hard Law?
Persistent accountability gaps reveal a clear tension between the global reach of business and the fragmented scope of legal enforcement. While the UNGPs and emerging due-diligence laws have advanced corporate responsibility, access to remedy remains uneven and enforcement inconsistent.
To bridge this divide, the UN Business and Human Rights Treaty process, led by the Office of the High Commissioner for Human Rights (OHCHR) and the Open-Ended Intergovernmental Working Group (OEIGWG), seeks to convert voluntary principles into binding obligations. The draft Legally Binding Instrument (LBI) aims to clarify States’ duties to regulate corporate conduct and strengthen access to justice for affected communities. This process complements the growing wave of mandatory human rights and environmental due diligence (mHREDD) laws across jurisdictions, reflecting an emerging convergence between national legislation and international law.
At the same time, the Council of Europe’s 2025 Report on Human Rights and Competitiveness notes that implementing due-diligence measures costs companies, on average, only 0.13 per cent of shareholder payouts, a modest investment compared with the social and financial risks of inaction.
Whether through progressive domestic regulation, regional directives or a future international treaty, the direction of travel is clear: corporate accountability is shifting from aspiration to enforcement.
Soft law, it seems, is no longer soft; it is quietly hardening both the conscience and the architecture of international law.
Author
Kübra Kalkandelen
Associate Director & Human Rights Lead, RSK International Projects Group
LLM in International and Commercial Dispute Resolution
MSc in Human Rights Policy and Practice
Bibliography
- Council of Europe (2025). Report on Human Rights and Competitiveness. Strasbourg.
- Muchlinski, P. (2021, 3rd ed.). Multinational Enterprises and the Law. Oxford: Oxford University Press.
- Ruggie, J. G. (2013). Just Business: Multinational Corporations and Human Rights. New York: W. W. Norton & Company.
- Zerk, J. A. (2006). Multinationals and Corporate Social Responsibility: Limitations and Opportunities in International Law. Cambridge: Cambridge University Press.