Rathbones, a UK wealth and asset management firm, has identified 194 instances of non-compliance with UK modern slavery reporting requirements across 160 FTSE 350 companies over the past six years, according to analysis published through its Votes Against Slavery initiative.
The findings, set out in a report titled Votes Against Slavery 2020-2025: Six Years, Six Lessons, draw on six years of engagement with UK-listed companies and highlight persistent weaknesses in corporate transparency and accountability.
The report found that more than 90% of non-compliance cases identified through the initiative were subsequently addressed by companies, which Rathbones said points to the potential influence of investor engagement and voting activity.
Modern slavery is estimated to affect around 50 million people worldwide, of whom about 28 million are in forced labour, according to the report. It noted that although the UK’s Modern Slavery Act 2015 brought in significant reporting obligations, uneven compliance and enforcement still leave vulnerable people, companies and investors exposed to risk.
The report sets out six key lessons from the six years of engagement. The first is that compliance failures remain widespread, with instances of non-compliance identified across 160 FTSE 350 companies, showing that reporting failures are not isolated cases.
The second lesson is that board oversight remains a recurring issue, with the most common compliance failure being the absence of board approval for modern slavery statements, highlighting weaknesses in governance and accountability.
The third lesson is that basic reporting requirements continue to be missed, with companies making avoidable errors including publishing statements incorrectly or covering the wrong reporting period.
The fourth lesson is that transparency alone does not drive change. Disclosure requirements have increased visibility of modern slavery risks but have not consistently translated into visible, adequate management of those risks, the report found.
The fifth lesson is that investor stewardship can be highly effective, with the Votes Against Slavery initiative achieving a compliance success rate of more than 90%, indicating that sustained investor engagement can support improvements in reporting compliance.
The sixth lesson is that human rights due diligence is the next frontier, with the report arguing that companies need comprehensive and proportionate human rights due diligence frameworks to help identify and address modern slavery risks across their operations and supply chains.
Archie Pearson, Stewardship Manager at Rathbones, said: “Six years of Votes Against Slavery has shown that modern slavery reporting failures remain surprisingly common among some of the UK’s largest listed companies. While the initiative’s compliance success rate of more than 90% demonstrates the power of investor engagement, recurring failures point to broader weaknesses in board oversight and a continued misunderstanding of reporting requirements.”
Pearson added: “The most important lesson from six years of engagement is that disclosure alone is not enough. What is needed is a comprehensive and proportionate human rights due diligence framework that supports companies in identifying and addressing modern slavery risks throughout their operations and supply chains.”
The report argues that while the UK Modern Slavery Act was groundbreaking when introduced, persistent compliance failures suggest the current reporting regime is no longer sufficient on its own to drive the behavioural change needed to combat modern slavery effectively.