Anti-Slavery Day on 18 October arrives as central government changes how it treats modern slavery in some central government procurement. From 1 January 2027, PPN 026: the Social Value Model will focus on good jobs, and skills, without a dedicated modern slavery assessment criterion.
This should not be misunderstood as a reduction in employer expectations. Modern Slavery has not been removed from government procurement. ‘PPN 009: Tackling modern slavery in government supply chains’ continues to guide procurement policy for identifying and managing risks. That ongoing oversight sits alongside a wider focus on supply chain security, particularly for defence and critical infrastructure, where there is growing need to demonstrate greater visibility and control of the supply chains delivering
For responsible employers, preventing modern slavery must also remain an ethical priority, alongside the legal and contractual requirements that apply to them.
Knowing who is behind delivery
Construction runs on networks of specialist contractors, suppliers, labour providers and manufacturers. Giving customers confidence means knowing who is working on their projects, how they were recruited and who employs and pays them, whether right-to-work checks are complete, where materials originate, and whether workers can raise concerns safely.
That means mapping the chain for workforce vulnerability, recruitment, subcontracted labour, material sources, welfare and governance, then testing how controls actually work on site rather than relying on policies and process. No one can guarantee a complex supply chain is free of risk. The credible position is having the relationships, information and controls to identify concerns and act on them.
Addressing the decisions that create risk
Modern slavery risk doesn't come only from deliberate misconduct. Unrealistic programmes, poorly designed work packages, excessive subcontracting, and heavy reliance on agency labour all create conditions that can increase vulnerability and make exploitation harder to identify. Due diligence has to begin before anyone reaches site. Our market knowledge helps us assess whether the necessary skills and capacity exist and challenge flawed assumptions before they are built into delivery.
Trust supported by evidence
At Willmott Dixon, assurance starts with long-standing relationships with our partners, reinforced through supply-chain mapping, structured onboarding, compliance checks, training, contractual requirements. These controls are embedded in our procurement policies and Supply Chain Code of Conduct.
Since 2022, we have completed 31 ethical labour audits with our supply chain partners. Our Modern Slavery Assessment Tool (MSAT) score is 89%, and 92% of our Category A partners have completed training and demonstrated relevant controls in place.
We have also worked with Unseen to develop our on-site response plan, training relevant operational colleagues as escalation points so concerns are reported and addressed consistently. Over the past 4 years we have competed two full investigations following concerns raised about supply chain partners and taken appropriate action in response. We believe effective due diligence means being willing to bring concerns into the open, investigate them and act – even when those actions challenge the status quo.
The same scrutiny reaches materials: we examined polysilicon supply chains and used what we learned to improve how we procure higher-risk products, namely photovoltaic panels.
Putting due diligence within reach of smaller firms
Smaller firms often recruit, employ and supervise the specialists for our sites. Due diligence needs to be practical for them too - we can’t depend on due diligence processes that require every supplier to have a compliance team.
In response, we worked with the Supply Chain Sustainability School’s Built Environment Against Slavery Group to develop a free due diligence assessment that lets an SME review its approach, find gaps and get practical actions and resources. Nearly 900 companies have completed the assessment, more than 700 of them SMEs. It is shortlisted for Innovation at the Unseen Business Awards 2026, with winners announced on 22 October.
From ethical responsibility to strategic capability
Protecting workers is first and foremost an ethical responsibility. The same supply-chain knowledge strengthens operational resilience and provides a foundation for wider customer scrutiny of personnel, labour providers and material provenance, including in defence and critical infrastructure.
Knowing who and what sits behind delivery also helps us respond to concerns and give customers confidence in how their projects are delivered.
Read our 2026 Modern Slavery Statement