Raising the Bar: How Corporate Codes of Ethics Can Strengthen Responses to Modern Slavery

Tags: Code of Ethics , Human rights

As the UK marks ten years since the Modern Slavery Act was passed, the new Home Office guidance on Section 54 signals a long-overdue shift: from checking boxes to protecting people. The latest expectations urge companies to move beyond minimal compliance and focus on meaningful, worker-centered action.  One of the most powerful tools they have in doing so is their Code of Ethics.

Our research examined how companies’ Modern Slavery Statements (MSS) and Code of Ethics (CoE) interlink and, as a first step, we conducted a content analysis of FTSE100 MSS and CoE documents over a period of five years between 2019 and 2023. For the purposes of our research, we use the term CoE to refer to documents that articulate core values, behavioural expectations and accountability mechanisms, regardless of their actual title.

We found that, while many firms improved their modern slavery disclosures over the five-year period, it is the quality and clarity of their CoE and its alignment with modern slavery statements that distinguishes substantive commitment from symbolic compliance.

Companies with clearer, more accessible and action-oriented CoE consistently demonstrate stronger governance, transparency and due diligence; and these principles are now reinforced in the revised guidance, which emphasises practical steps to prevent, identify and respond to modern slavery.

 

Quality Codes, stronger protection against modern slavery

High-quality CoE are those marked by clear language, user-friendliness, senior leadership emphasis and Speak Up support. These Codes were significantly associated with better quality of modern slavery statements. Where ethical principles were embedded in governance mechanisms and linked to supply chain accountability, MSS demonstrated a stronger sense of substance and integrity.

A notable finding was that many companies cross-referenced their CoE in their Modern Slavery Statements. Where this integration was more extensive, the corresponding Codes had more clarity in tone, were more user-friendly, and were better aligned with internal accountability and reporting structures. This suggests that congruence across the two documents appears to be an indicator of serious intent.

Good practice examples

• GSK links its Code of Conduct to a broader human rights framework. This connection informs its use of modern slavery risk indicators, such as sector, geography and workforce profile, to trigger enhanced due diligence for high-risk suppliers. The Code is explicitly referenced in GSK’s Modern Slavery Statement, reinforcing its role in setting clear ethical expectations across the supply chain.
• Centrica also embeds its Code of Conduct into supplier relationships, integrating it into onboarding, audit processes and contracts. While its Modern Slavery Statement focuses more on specific policies and due diligence, it draws on the principles outlined in the Code to indicate supplier accountability and alignment with ethical standards.

 

Transparency that goes beyond the First Tier of suppliers

The revised Home Office guidance encourages companies to assess and report on risks to workers, not just reputational risks. Among FTSE 100 firms, those with stronger CoE were more likely to disclose information on their second-tier suppliers and beyond, as well as their operational footprints. By contrast, those with vague or inaccessible Codes were more likely to report minimal action or none at all.

Good practice examples

• Shell embeds modern slavery commitments into its Code of Conduct, supported by site audits (both announced and unannounced), supplier compliance through its Worker Welfare Manual and internal reporting via whistleblowing channels, all referenced in its Modern Slavery Statement.
• BAT, similarly, links its Standards of Business Conduct to regional CSR and audit committee oversight, ensuring that modern slavery risks, explicitly addressed in its Modern Slavery Statement, inform governance decisions and supplier accountability across its operations.

Such practices reinforce the idea that CoE are not symbolic; they can be substantive in the sense that they communicate the norms and expectations that filter through procurement systems and supply chains and signal on expected behaviours.

 

Embedding worker voice and continuous improvement

A key emphasis in the revised guidance is “worker voice”, i.e. encouraging companies to consult with workers, engage with unions, and ensure that grievance systems are functional and trusted. Our research found growth in grievance mechanisms over the years but a decline in engagement with independent representatives, raising concerns about the depth and authenticity of worker input.

Good practice examples

Our evidence suggests that companies with stronger CoE, especially those highlighting Speak Up cultures, were more likely to report structured grievance pathways, training, and non-retaliation commitments. For example, Shell outlines how its internal reporting is supported by trained case managers and formal escalation channels to ensure that reported concerns are investigated and addressed effectively. Similarly, Diageo supports multilingual grievance systems, with findings reported back to relevant business units and suppliers to enable incorporation of the concerns.

These elements speak to the principle of continuous improvement, not simply reporting what has been done but showing how systems evolve and respond.

 

Disclosure with purpose

The revised guidance encourages companies to be transparent about risk findings, not to avoid disclosures out of fear, but to use them as a foundation for remediation. This reflects a growing expectation that modern slavery reporting is not about avoiding failure but about showing maturity in governance.

Good practice example

• Our analysis highlights that companies with clearer, well-integrated CoE were more likely to disclose third-party audit results, corrective actions, and remediation plans. BAT, for example, uses Independent Due Diligence Assessments to evaluate supplier practices, identify gaps in human rights performance, and report findings through public statements and internal governance channels. Where risks are identified, targeted action plans are developed, monitored and integrated into broader compliance strategies.
  
  This approach illustrates the value of transparency that is purposeful and constructive, aligned with the spirit of Section 54’s revision.

 

Codes that mean something

As companies respond to the new guidance, a central question arises: Does the Code of Conduct serve as a substantive tool for protecting people or simply a symbolic gesture of compliance?

In organisations where a CoE is cross-referenced in the Modern Slavery Statement, reinforced through training, and embedded across procurement and oversight systems, it becomes central to an effective ethical governance system. Where the Code is generic or disconnected from operational systems, its impact is significantly weakened.

Embedding values into governance, due diligence and worker engagement strengthens both ethical practice and long-term resilience. When strategically aligned with governance systems and operational practices, these Codes do more than communicate standards - they form the tool to enable accountability. As expectations rise and scrutiny deepens, companies that treat their Codes as living ethical frameworks - not just formalities - will be best placed to lead by example, setting industry standards for ethical governance, transparency and worker-centred due diligence.

As this research is ongoing, please feel free to contact the IBE or the writers directly, for more information.

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