Dame Sara Thornton calls for more industry collaboration and government leadership to tackle labour exploitation in construction


Independent Anti-Slavery Commissioner Dame Sara Thornton has today published a report which examines the risks and drivers of labour exploitation in the construction sector. The report analyses a major police investigation, Operation Cardinas, in which a Romanian organised crime group (OCG) infiltrated the supply chains of major construction projects across London and the southeast for nearly a decade.


The OCG placed an estimated 300 to 500 Romanian victims onto commercial, residential and demolition projects between 2009 and 2018. Locations ranged from prestigious developments in the capital to regional housing schemes.


The Metropolitan Police identified at least 33 companies, including contractors, agencies and umbrella firm payroll providers, that had unwittingly been paying into accounts controlled by the OCG. Cumulative transactions for each business ranged from £100s to £100,000s. However, investigators believe that the identified businesses represented only a fraction of those impacted by this long-operating gang.


This report examines the criminal tactics used to circumvent site security and safeguarding protocols, identifying opportunities that were missed by co-workers, site managers and payroll departments in spotting the signs of slavery. It also hears from one company that became caught up in Operation Cardinas, and the actions that it took to protect victims while the investigation continued.


Construction is one of the UK’s largest and most important economic sectors. However, it has consistently been cited as at high risk of labour exploitation by successive Directors of Labour Market Enforcement. The government also identified construction as one of three priority risk areas for departmental procurement in its modern slavery statement of 2020.


While Operation Cardinas is an extreme example of criminality intersecting with legitimate business, lower levels of labour exploitation are routinely found in the sector. Contractors face particular challenges in managing this risk, including:


  • The high turnover of workers on building sites which makes it difficult to process and monitor individuals.
  • The sector’s heavy reliance on temporary and migrant labour
  • The complex network of subcontractors and labour agencies, resulting in poor visibility of worker conditions at lower levels of supply chains.


In addition, contractors are grappling with a chronic skills shortage and a dwindling supply of workers from the European Union post pandemic and Brexit.


The IASC office interviewed more than 15 organisations - including many principal contractors - to understand the challenges they face in the ethical management of labour. Concerns ranged from the difficulty for site teams in interpreting complex visa arrangements to the discovery of individuals working without contract, and whose pay packets were subject to dubious deductions.


Good practice identified within the sector included;


  • Cross-departmental modern slavery working groups
  • On-site worker engagement initiatives and worker interviews
  • Deeper dives into supply chains through audits, visits and targeted training
  • Multi-stakeholder projects, where competitors share data and intelligence to improve audit strategy, enhance training and identify other practical interventions.
  • An example of an ethical management system - a systemic approach to labour management, encompassing internal operations, supplier relationships and the site workforce
  • Strategies and targets to reduce reliance on temporary labour


Read the report here.



Dame Sara Thornton, Independent Anti-Slavery Commissioner, commented:

“Construction is a major employer and vibrant part of the UK economy. An estimated 2.2 million people are working on the buildings and infrastructure that form the backdrop to our everyday lives. 

While the sector is striving to meet its sustainability and carbon targets, it faces particular challenges in the ethical management of labour. Operation Cardinas is a harrowing reminder that no organisation can afford to be complacent, and that every worker has a role to play in spotting the signs.

I would like to thank all the organisations that contributed to this report. It is encouraging to see a number of joint initiatives progressing. I hope that more contractors will be persuaded to join them in a spirit of openness and sharing. Collaborative working is critical for tackling criminality, poor compliance and ruthless opportunism. The support, understanding and strong leadership of clients will also be essential setting the right tone and driving cultural change.

However, the difficulties that businesses are experiencing in providing effective support to workers, and battling non-compliance in supply chains, underlines the pressing need for government to provide more guidance and leadership across the spectrum of issues.

I hope that the government’s plans to create a Single Enforcement Body, bringing together the Gangmasters and Labour Abuse Authority, the Employment Agency Standards Inspectorate and HMRC’s National Minimum Wage team, will provide a more coherent platform for support, helping to drive up standards while simultaneously holding businesses to account.”






Notes to editors

  • Part 4 of the Modern Slavery Act 2015 created the role of the Independent Anti-Slavery CommissionerThe Commissioner has a UK-wide remit to encourage good practice in the prevention, detection, investigation and prosecution of slavery and human trafficking offences and the identification of victims.
  • The Commissioner is given an annual budget with which to appoint staff and carry out her duties. She is accountable through her strategic plan and annual reports, which the Secretary of State lays before Parliament, setting out the extent to which objectives and priorities are achieved. Her Strategic Plan 2019 – 2021 was launched in October 2019 and her Annual Report 2020 – 2021 was launched in July 2021.
  • Dame Sara Thornton was appointed as the Independent Anti-Slavery Commissioner by the Secretary of State following consultation with the Scottish Ministers and the Department of Justice in Northern Ireland. She took up post at the beginning of May 2019 and her appointment is for three years.

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