Constructive Dismissal: Establishing the Fundamental Breach in 2025

The Legal Framework

Constructive dismissal arises where an employee resigns in response to a fundamental breach of contract by the employer. The most commonly relied-upon term is the implied term of mutual trust and confidence: that neither party will, without reasonable and proper cause, conduct themselves in a manner calculated or likely to destroy or seriously damage the relationship of trust and confidence between employer and employee (Malik v BCCI [1997] UKHL 23).

The employee must resign in response to the breach, must not delay unduly, and must not have affirmed the contract by continuing to work after the breach.

Key Principles Reaffirmed in 2025

The "Last Straw" Doctrine

The "last straw" doctrine allows an employee to rely on a series of incidents, each of which may be individually insufficient to constitute a fundamental breach, but which cumulatively amount to one. The final act need not itself be a breach of contract, but it must not be entirely innocuous.

In Kaur v Leeds Teaching Hospitals NHS Trust [2019] EWCA Civ 2225 — still the leading authority — the Court of Appeal confirmed that the question is whether the employer's conduct, viewed as a whole and cumulatively, amounted to a fundamental breach. Recent 2025 tribunal decisions have continued to apply this test, emphasising that tribunals must consider the full history of the relationship, not just the final act.

Affirmation and Delay

A recurring issue in 2025 cases has been the question of affirmation. An employee who continues to work for a significant period after the alleged breach may be taken to have affirmed the contract, losing the right to resign and claim constructive dismissal.

The key question is whether the employee's conduct is consistent only with acceptance of the breach, or whether it is consistent with protest and continued performance under duress. Employees who raise grievances, seek legal advice, or expressly reserve their position are less likely to be found to have affirmed.

Fundamental Breach vs. Poor Management

A consistent theme in recent decisions is the distinction between conduct that amounts to a fundamental breach and conduct that is simply poor management. Unreasonable behaviour, unfair treatment, or a failure to follow procedure does not automatically give rise to a constructive dismissal claim. The question is always whether the employer's conduct, objectively assessed, crossed the threshold of a fundamental breach.

Practical Guidance for Employees

If you are considering resigning and claiming constructive dismissal:

1. Act promptly. Do not delay unduly after the breach. If you continue to work, document your reasons and make clear you are not accepting the breach.
2. Raise a grievance. This is not strictly required, but it creates a contemporaneous record of your objections and may assist your case.
3. Seek advice before resigning. Constructive dismissal claims are notoriously difficult to establish. Take legal advice before you resign.
4. Keep records. Emails, messages, and notes of meetings can be critical evidence.

Practical Guidance for Employers

1. Investigate grievances promptly and fairly. A failure to deal with a grievance can itself contribute to a finding of constructive dismissal.
2. Avoid cumulative conduct. A series of minor incidents can cumulatively amount to a fundamental breach even if no single incident would do so.
3. Follow your procedures. Departures from contractual or policy procedures can contribute to a finding of breach.

Christopher Mallon BL represents employees and employers in constructive dismissal claims before the Employment Tribunal. Direct access instructions are welcome.