Modern Slavery

18% of global forced labour victims work in the construction industry

An estimated 50 million people are living in modern slavery worldwide, including 27.6 million in forced labour. Construction is particularly high risk, with an estimated 2.6 million adults experiencing forced labour exploitation globally working in the sector.

Modern slavery is not just a global supply chain issue, estimates suggest there are 130,000 victims of modern slavery here in the UK. In 2025, Unseen’s Modern Slavery & Exploitation Helpline recorded 710 potential victims across 150 construction-related cases, a 44% increase in potential victims compared with 2024.

The built environment is particularly high-risk due to high labour demand, skills shortages, long and complex supply chains, and the widespread use of subcontracted, migrant and self-employed labour. One of the UK’s largest modern slavery investigations, Operation Cardinas, unravelled how an organised crime group placed more than 500 victims of modern slavery onto major construction sites in the South-East over almost a decade. Risks extend beyond construction sites and direct workforces into the global supply chains that provide materials, products and services.

Around the world, legal, investor and client expectations around modern slavery are evolving. Increasingly, governments are insisting on human rights due diligence with a steady increase in criminal and civil enforcement actions being taken. Businesses can no longer afford to turn a blind eye to exploitation in their operations and supply chains. They must take proactive and proportionate steps to identify, prevent, mitigate and manage modern slavery risks.

How well equipped is your organisation to:

Understand its responsibilities under the Modern Slavery Act 2015 and evolving due diligence expectations?
Identify and assess modern slavery risks across its operations, workforce and wider supply chains?
Spot the signs of exploitation and ensure workers have safe, accessible ways to raise concerns?
Embed responsible recruitment, procurement and supplier management practices that reduce the risk of exploitation?
Respond appropriately when concerns arise, including escalating incidents, safeguarding workers and providing victim-centred remediation?
Measure progress, demonstrate effective due diligence and continually improvement its approach?

Modern Slavery Due Diligence Assessment

Take the assessment

Not sure where to start?

Work with your company administrator to complete the School’s free, confidential Modern Slavery Due Diligence Assessment.

It helps organisations of any size assess their current approach, benchmark performance and receive a tailored action plan linked directly to free tools, training and resources.

Since launching in October 2025, the assessment has supported more than 1,000 assessments and reassessments, with around 80% completed by SMEs, and won the Unseen Business Award for Innovation.

Can’t access the assessment or don’t know who your company administrator is? Contact [email protected].

A practical guide to

Addressing modern slavery and labour exploitation in the built environment

These resources will support your due diligence approach by helping you to prevent, identify, manage, mitigate and remediate modern slavery and labour exploitation risks, across your operations and supply chains.

These headings align with the key themes outlined in BS 25700 – Organisational Responses Modern Slavery and the Transparency in Supply Chains (TISC) government guidance.

Explore more themes

1. Policy

Select a resource below

The Modern Slavery Act

E-learning Module

Key points you need to know about the Act and how it affects your business.

Intermediate

15 minutes

Sustainability

Search our catalogue of FREE training resources

18% of global forced labour victims work in the construction industry

Modern Slavery Due Diligence Assessment

The Modern Slavery Act

UN Guiding Principles on Business and Human Rights

ILO Guidelines For A Just Transition

PPN/009: Guidance on tackling modern slavery in government supply chains

WageIndicator Work in the UK: Wages and Worker rights

Modern Slavery Statements, the Modern Slavery Registry and Policies: Webinar Recording

Human rights due diligence framework

Supporting a Just Transition

Salient human rights issues

UN Guiding Principles Reporting Framework

Beyond compliance in the renewable energy sector

Modern Slavery Statement Registry

Tackling modern slavery in UK service and infrastructure projects

Modern Slavery Assurance Guidance

EU: Due diligence to address the risk of forced labour

Brickmakers Quality Charter

GLAA – strategic assessment

Implications of the Modern Slavery Act

Tackling Modern Slavery in Solar PV Supply Chains: Challenges, Drivers, and Practical Guidance

Tackling Modern Slavery Through Purchasing Practices

Construction and the Modern Slavery Act: Tackling Exploitation in the UK (CIOB)

Tackling modern slavery in UK service and infrastructure projects

A toolkit for organisations in construction and property

UN Guiding Principles on Business and Human Rights

Enablers for Delivering Modern Slavery Due Diligence: Webinar Recording

Case Study: Sky Innovation Centre

Addressing modern slavery in long and complex supply chains

Operation Cardinas: Addressing exploitation risk in the construction sector

EU: Due diligence to address the risk of forced labour

Modern Slavery Benchmark Tool

Corporate human rights benchmark

Combatting forced labour: a handbook for employers and businesses

Modern Slavery Assurance Guidance

Supporting a Just Transition

The UK Government Modern Slavery Statement

UN Guiding Principles Reporting Framework

Universal Human Rights Index Database

A just transition explained

Beyond compliance in the renewable energy sector

Business and human rights resource centre

Enabling a just transition of the built environment

Human rights due diligence framework

ILO Guidelines For A Just Transition

Respecting rights in renewable energy

PPN/009: Guidance on tackling modern slavery in government supply chains

SA 8000

Operational Toolkit: Combatting Slavery in the Built Environment

A Practical Guide to Understanding Modern Slavery Risk in Supply Chains

List of goods produced by child labour or forced labour

Worker wellbeing in construction – Unseen’s findings and what you can do

GLAA – strategic assessment

Tackling Modern Slavery in Solar PV Supply Chains: Navigating Risk – Webinar Recording

Global Rights Index

Marshalls Modern Slavery Risk Analysis

Case Study: Sky Innovation Centre

Design for Freedom International Guidance and Toolkit

Slavery and Trafficking Risk Template

Corporate human rights benchmark

Combatting forced labour: a handbook for employers and businesses

Modern Slavery Assurance Guidance

Tackling modern slavery in UK service and infrastructure projects

Child rights risks in global supply chains: why a ‘zero tolerance’ approach is not enough

Comply Chain App

Evaluating The Risk Of Modern Slavery And Labour Exploitation In Your Supply Chains: Webinar Recording

Identifying labour exploitation

Indicators of forced labour

Spotting the signs of modern slavery

Supply Chain Mapping and Modern Slavery

CSCS Smart Check

Modern Slavery E-learning Module

Operational Toolkit: Combatting Slavery in the Built Environment

Beyond the Shadows – Unseen

Concrete – Tackling Modern Slavery in the Construction Sector

Spot the Signs Posters

A toolkit for organisations in construction and property

Procurement Guidance: Best Practice in Combatting Modern Slavery – Update in progress