The BBC’s latest investigation into illegal working has exposed the lengths some will go to circumvent the UK’s enforcement system. The investigation uncovered a solicitor allegedly offering to make a £45,000 illegal-working fine disappear by arranging for an individual overseas to declare themselves the owner of a mini-market facing a penalty for employing an illegal worker.
In response, Home Secretary Shabana Mahmood has announced a review of the way these fines are issued and collected.
For the construction industry, the investigation should serve as a stark warning. As new legislation extends liability through contractual chains and enforcement activity increases, principal contractors face growing financial and reputational exposure if they cannot demonstrate effective oversight of their supply chains.
Robert Brent, CEO of construction workforce management solutions provider MSite, warns of the growing financial and reputational risks facing principal contractors as tougher illegal-working legislation and increased enforcement place greater scrutiny on construction supply chains.
“The BBC’s investigation exposes a much wider problem. Illegal working is not always the result of an overlooked document or an administrative error. It can involve deliberate attempts to circumvent the very systems designed to prevent it.
“For construction, where thousands of workers can operate across multiple subcontracting tiers, this raises serious questions about how effectively businesses understand and oversee their supply chains.
“Principal contractors must wake up to the risks within their supply chains before the financial and reputational consequences threaten their ability to operate.
“The reality is that many principal contractors have limited visibility of who is actually delivering work beyond their immediate subcontractors. With the legislative changes introduced on 1 October extending accountability further up the chain, that lack of oversight now carries significant risk, particularly as the Home Office and HMRC enforcement intensifies, and the consequences of non-compliance become increasingly severe.
“Under Section 48 of the Border Security, Asylum and Immigration Act 2025, the Right to Work regime has expanded to cover additional working arrangements. While direct employers remain responsible for conducting the prescribed checks, new extended-liability provisions mean civil penalties can reach further up the contractual chain, including principal contractors who do not directly employ the individuals involved.
“The financial implications are substantial. Civil penalties can reach £45,000 per illegal worker for a first breach and £60,000 for repeat breaches. Across major construction projects, even a handful of breaches could have devastating consequences for a contractor’s bottom line and reputation.
“Enforcement is already intensifying. During the first six months of 2026, the Home Office carried out 268 illegal-working visits on construction sites, a 150% increase on the same period in 2025. Arrests also rose by 29%.
“These figures make one thing clear: construction businesses can no longer afford to rely on paperwork and compliance checks alone to protect themselves from illegal working risks.
“Most responsible contractors already have compliance processes established. The challenge is whether those processes provide a reliable picture of what is happening beyond their immediate subcontractors.
“A worker passing a Right to Work check does not, on its own, demonstrate that a principal contractor has the necessary controls in place to address its wider legal exposure.
“Contractors need to understand who employs or engages each worker, where those relationships sit within the contractual chain, whether the approved supply chain reflects what is happening on site, and what evidence exists to demonstrate effective oversight.
“That requires greater coordination between procurement, HR, legal, commercial and operational teams. Each holds part of the picture, but effective assurance depends on connecting that information and demonstrating that the appropriate controls are working.
“The BBC investigation is an uncomfortable reminder that declared business relationships and paperwork alone cannot always be relied upon to reveal the reality.
“Contracts establish how a supply chain should operate. Assurance requires evidence of how it actually operates.
“For an industry built on complex, multi-tier arrangements, this represents a significant shift. It is about understanding the wider supply chain, identifying the risks before they escalate and demonstrating that appropriate safeguards are in place.
“With legislation tightening and enforcement increasing, principal contractors have an opportunity to address potential gaps before they become costly consequences.”
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