Harriet PriceThe UK's national terrorism threat level has been raised to "severe" in May 2026, meaning an attack is considered "highly likely". The United States Embassy in London simultaneously issued a warning advising American citizens to avoid schools, churches, tourist sites, and transport hubs. For the millions of UK employers who manage staff in public-facing locations, this is not just a news story — it is a legal obligation trigger.
What "Severe" Actually Means Under UK Law
The UK threat level system runs from "low" through "moderate," "substantial," "severe," and "critical." A "severe" rating means security services assess that a terrorist attack is highly likely in the current period, though no specific plot may be confirmed.
This distinction matters for employers because UK health and safety law — particularly the Health and Safety at Work Act 1974 and the Management of Health and Safety at Work Regulations 1999 — requires employers to assess and respond to foreseeable risks to their employees. When the state formally elevates the national threat level to "severe," that assessment becomes part of the foreseeable risk landscape. Ignoring it is not a defensible position.
According to the UK government's official guidance on terrorism and national emergency, businesses should review their protective security measures and emergency plans whenever the threat level changes. This is not voluntary best practice — it is a dimension of the employer's ongoing duty of care.
The Five Legal Obligations That Apply Right Now
1. Review and update your risk assessment. The Management of Health and Safety at Work Regulations 1999 require employers to carry out "suitable and sufficient" risk assessments covering all reasonably foreseeable risks. A formally elevated threat level makes terrorism a foreseeable risk in any workplace operating in or near public-access locations, transit hubs, crowded places, or symbolic buildings.
If your last risk assessment predates the current "severe" rating, it is no longer current. Employers with five or more staff must record the significant findings in writing. Employment lawyers advise doing this immediately — a risk assessment completed after an incident, rather than before, provides far weaker legal protection.
2. Review your emergency response plan. Does your organisation have a written "action on" plan for a security incident? Does every employee know what to do if there is a firearms or weapons attack on or near the premises? The National Counter Terrorism Security Office (NaCTSO) provides free "Action Counters Terrorism" training for businesses. During a "severe" alert period, scheduling this training signals reasonable steps taken. Failing to schedule it during a known elevated risk period increases your exposure.
3. Consider your duty of care to lone workers and field staff. Employers have the same duty of care to staff working remotely, visiting clients, or travelling as to those in the office. If your organisation has field workers, delivery staff, or employees who regularly visit public venues, you need to have communicated the elevated threat level and provided guidance on what to do if they feel unsafe. This includes clear escalation routes and the right to remove themselves from a situation they assess as dangerous.
4. Assess your public-facing premises. Businesses operating in locations specifically named in the US Embassy advisory — near schools, places of worship, tourist attractions, and transport hubs — carry heightened legal exposure. If your premises are adjacent to any of these categories, security assessments should document what physical measures are in place: CCTV coverage, bag checks if applicable, staff awareness training, and evacuation procedures. Inadequate security in a publicly accessible building during a "severe" threat period can constitute a breach of the Occupiers' Liability Acts.
5. Document everything you do. In the event of a subsequent incident, documentation of proportionate steps taken during the elevated threat period will be the foundation of any legal defence. Records should include the date the risk assessment was updated, who was consulted, what measures were introduced or reviewed, and who was briefed.
What Employees Can Legally Demand
The elevation of the threat level also affects employee rights. Under Section 44 of the Employment Rights Act 1996, an employee has the right to refuse to work in conditions they reasonably believe pose a serious and imminent danger to their health and safety. An employee who declines to work in a public-facing role during a confirmed "severe" threat period, without their employer having taken visible and proportionate steps, may have a protected ground for doing so.
This does not mean that any expression of unease entitles an employee to stay home. The test is "serious and imminent" — but a nationally elevated threat level, combined with embassy alerts advising avoidance of specific location types, creates a stronger factual basis for that argument than the same claim made during a "moderate" threat period.
Employment law solicitors are already handling queries on this question. Employers who have not briefed their staff, updated their risk assessments, or reviewed emergency protocols face a more difficult legal position if a Section 44 dispute arises.
What a Legal Expert Would Advise
The practical advice from employment lawyers and health and safety specialists converges on a short, urgent list: act now, document everything, and do not wait for the threat level to change back before closing your compliance gaps.
For larger organisations — particularly those operating in hospitality, transport, retail, or education — a formal legal review of protective security obligations during an elevated threat period is advisable. For smaller employers, a documented conversation with an employment law solicitor covering risk assessment status, emergency plans, and staff communications can take less than an hour and create a clear paper trail.
Explore how UK employment rights interact with national emergency powers
The threat level will eventually return to "substantial," but the legal obligation to have acted reasonably during the "severe" period does not expire when the level drops. Employers whose response was inadequate during the elevated period remain exposed to claims after the fact. Acting now is both the legally correct course and the practically prudent one.
This article provides general legal information only. Individual employment and health and safety circumstances vary. Please consult a qualified employment law solicitor or health and safety legal specialist for advice specific to your organisation. ExpertZoom connects UK employers with qualified employment law solicitors available for urgent consultations.
