What Is Constructive Dismissal? A UK Employee's Guide
Constructive dismissal happens when an employer commits a serious breach of your employment contract and you resign in response. This guide explains the legal test, what counts as a fundamental breach, the rules you must follow, and the time limits for making a claim.
Last updated: July 2026. This guide provides general information, not legal advice.
What is constructive dismissal?
Constructive dismissal happens when your employer commits a serious breach of your employment contract — known as a repudiatory breach — and you resign in response to that breach. Although you chose to resign, the law treats it as a dismissal by the employer.
The legal test comes from the leading case Western Excavating v Sharp: the employer must be in fundamental breach of a term of the contract (express or implied), and the employee must resign in response to that breach — not for some other reason.
What counts as a fundamental (repudiatory breach)?
A repudiatory breach goes to the root of the contract. The most common implied term relied on is the duty of mutual trust and confidence. Examples can include:
- A unilateral and substantial cut in pay or demotion without agreement
- Serious and continued bullying or harassment that the employer fails to address
- Forcing you to work in dangerous conditions in breach of health and safety duties
- A serious breach of the disciplinary or grievance procedure that deprives you of a fair hearing
- Unjustified suspension for prolonged periods, or exclusion from work without cause
- Changing your role, location, or hours in a way that fundamentally alters the contract
Minor or one-off irritations are not enough. The breach must be serious enough to justify resigning. Courts look at the whole picture, including whether a series of smaller breaches amounts to a fundamental breach (the "last straw" principle).
Key rules for a successful claim
1. Resign in response to the breach
You must resign because of the employer's breach. If you resign for an unrelated reason (such as a better job offer), the claim will fail.
2. Do not affirm the contract
Continuing to work for a long time after the breach, without objection, can be treated as accepting the breach and continuing the relationship ("affirmation"). Resign without undue delay once the breach (or the last straw) occurs.
3. Raise a grievance first where possible
Unless raising a grievance would be futile, doing so gives the employer a chance to remedy the breach and strengthens your position. Resigning without first complaining can weaken the claim.
4. Make clear you are resigning in response to conduct
Your resignation should state that you are resigning because of the employer's conduct and breaches. A vague resignation letter can create doubt about your reasons.
Service requirements and exceptions
For ordinary unfair dismissal, including constructive dismissal, you generally need 2 years' continuous service (1 year in Northern Ireland). However, some claims have no qualifying period:
Discrimination
If the breach involves discrimination under the Equality Act 2010 (age, disability, sex, race, etc.), there is no service requirement.
Whistleblowing
Dismissal (including constructive dismissal) for making a protected disclosure is automatically unfair with no qualifying period.
Time limits and how to claim
3 months less 1 day
The deadline runs from your last day of employment. ACAS early conciliation pauses this clock temporarily — but you must contact ACAS before the deadline expires. Do not wait.
The usual route is:
- 1Raise a grievance with your employer and give them a chance to address the breach.
- 2Resign clearly, stating you are doing so in response to the employer's conduct.
- 3Contact ACAS for early conciliation before the 3-month deadline.
- 4If conciliation does not settle the matter, lodge a claim at the employment tribunal.
Gathering evidence
Constructive dismissal claims are hard to win because you must show the breach was fundamental and that you resigned because of it. Strong evidence is essential:
- A written grievance and the employer's response
- Emails, letters and messages showing the conduct you complained about
- Witness statements from colleagues
- A chronology of events, especially the "last straw"
- Your resignation letter clearly linking the resignation to the breach
- Records of any impact on your health (GP letters, fit notes)
Tip: EmploymentCase helps you build a chronology, log issues and store evidence so you can demonstrate the breach and your response clearly.