- Whistleblowing protection has just widened. Since 6 April 2026, the Employment Rights Act 2025 made sexual harassment an explicit category of protected disclosure, closing a gap that previously forced these reports to be squeezed into other categories such as breach of a legal obligation.
- There is no minimum length of service and no cap on compensation. Unlike ordinary unfair dismissal, whistleblowing protection applies from day one of employment, and a tribunal can award uncapped compensation where someone is dismissed or subjected to detriment for blowing the whistle.
- The bar for protection is lower than most people assume. A worker does not need to be right, or use any particular language, only to hold a reasonable belief that the information tends to show wrongdoing and that raising it is in the public interest, and the courts have confirmed that a relatively small group of affected colleagues can be enough to satisfy that test.
Whistleblowing sits in an unusual position in employment law. It carries some of the strongest protections available to any worker, no service requirement, no compensation cap, yet it is also one of the most misunderstood, both by the employees deciding whether to raise a concern and by the managers who receive it. Getting the response right matters more than most employers realise.
What counts as a protected disclosure
To be protected, a disclosure needs to meet two tests. First, the worker must reasonably believe the information tends to show one of the categories of wrongdoing set out in law. Second, since reforms in 2013, they must also reasonably believe that raising it is in the public interest, not simply a personal grievance dressed up as a wider concern.
| Category of wrongdoing | What it covers |
| Criminal offence | Has been, is being, or is likely to be committed |
| Breach of a legal obligation | Any failure to comply with a legal duty, contractual or statutory |
| Miscarriage of justice | Has occurred, is occurring, or is likely to occur |
| Danger to health and safety | Of any individual, not only employees |
| Damage to the environment | Has occurred, is occurring, or is likely to occur |
| Deliberate concealment | Of information about any of the above |
| Sexual harassment | New since 6 April 2026, that it has occurred, is occurring, or is likely to occur |
The information does not need to be watertight, and the worker does not need to be a lawyer. What matters is whether the belief was reasonable at the time, based on what they knew.
How the protection actually works
A worker who makes a protected disclosure is protected from being subjected to a detriment because of it, and dismissing someone principally because they blew the whistle is automatically unfair. Both protections apply from an employee’s first day, with no qualifying period, and neither carries the cap that applies to ordinary unfair dismissal compensation.
Bad faith does not remove protection, but it can reduce compensation by up to 25% where a tribunal finds the disclosure was not made in good faith. On the public interest test itself, the Court of Appeal in Chesterton Global Ltd v Nurmohamed confirmed that a disclosure can still be in the public interest even where the worker also has a personal stake in it, in that case, a change to how commission was calculated that affected around 100 senior managers was enough to count as a section of the public, even though the worker raising it was one of them.
Building a whistleblowing process that works
- Set out a clear policy with more than one route to raise a concern, so someone uncomfortable approaching their own manager still has somewhere credible to go.
- Protect confidentiality as far as possible, and be explicit about what can and cannot be kept anonymous, rather than making a blanket promise that later cannot be kept.
- Actively guard against retaliation, not just in policy but in practice, since detriment is often informal, being quietly excluded or overlooked, rather than a formal sanction.
- Investigate promptly and proportionately, with genuine independence wherever the concern touches someone senior or internal impartiality is in doubt.
- Close the loop. Tell the person what happened as far as confidentiality allows, since a concern that disappears into silence discourages the next person from raising anything at all.
Common mistakes
- Treating whistleblowing as a policy document to have on file, rather than a process that is actually tested and followed when a concern is raised.
- Focusing the investigation on the whistleblower’s motives instead of the substance of what they have raised.
- Missing informal detriment, a change in tone, being left off things, sidelined from projects, because it does not look like retaliation on paper.
- Providing no feedback at all once a concern has been raised, leaving the person unsure whether it was taken seriously.
Getting it right
CMP investigates whistleblowing concerns as part of our wider workplace investigation service, including cases involving compliance, ethics and fraud, and we deliver training that helps managers respond to concerns promptly and fairly rather than instinctively, reducing the risk of the case escalating unnecessarily.
You can read more about our approach and experience, or get in touch to talk through a current concern.
