Constructive Unfair Dismissal – How serious does the 'last straw' need to be?

Constructive dismissal occurs when the employer commits a repudiatory breach of the employee’s contract – the breach can be express or implied – and the employee resigns in response to this breach. This is different to unfair dismissal where the employer terminates the employee’s employment contract.

Under Section 95 (1) (c) of the Employment Rights Act 1996 (ERA 1996), an employee is deemed dismissed if they resign in response to a fundamental breach of contract by the employer. This may arise from a single serious act, or where the single act is not deemed to be sufficiently serious to justify the employee resigning and claiming constructive dismissal, the employee may seek to rely on a series of breaches to cumulatively amount to a breach of the implied term of trust and confidence, usually with a final serious breach leading to resignation. This is referred to as the “last straw” doctrine.

A recent case suggests that the “last straw” need not be a serious breach of contract.

Marshall v McPherson Limited [2025] EAT 100 explores whether an employee can claim constructive unfair dismissal when the final incident or breach prompting the employee’s resignation is relatively minor but forms part of a broader course of conduct that undermines the duty of mutual trust and confidence that exists between employee and employer.

Facts:

Mr Marshall was an experienced HGV driver working night shifts for McPherson Limited. He worked alone, unloading deliveries. Following operational changes by the employer, Mr Marshall found it difficult to take rest breaks and raised this with his manager; however, the employer failed to address this. Subsequently and without warning, the employer sent another colleague to accompany Mr Marshall on shift and report back on his performance. Mr Marshall felt undermined and cited this, alongside his earlier concerns about working conditions, to resign and claim constructive unfair dismissal.

The Employment Tribunal dismissed his claims on the basis that there had not been a “last straw” to justify his resignation. They stated that neither the delay in handling his complaints nor the sending of a colleague was serious enough to justify a finding of constructive dismissal. However, the Employment Appeal Tribunal disagreed. It stated that a resignation can still amount to constructive dismissal even if the final event was relatively minor, provided it contributed to a wider breakdown in trust and confidence when considered alongside earlier breaches.

Whilst this decision does not significantly alter the legal tests that should be applied in constructive dismissal cases, it serves as a reminder of how employers should consider and treat constructive dismissal claims based on the “last straw” doctrine. We have seen the doctrine of constructive dismissal widened more recently, and more and more cases are being decided in favour of employees.

Employers should be aware of:

• The importance of taking employee concerns seriously. If an employee raises concerns, employers should document them and respond promptly and with transparency.
• The fact that a number of seemingly minor incidents could, when considered cumulatively, amount to a serious breach.
• Previous issues that employers may consider resolved can be considered when assessing the overall, cumulative pattern of treatment.
• The importance of conducting an overall assessment of their own behaviour and the facts, rather than assessing the most recent incidents in isolation.

To book an appointment or to discuss this further, please contact the Employment Law team on [email protected], 01732 770660

This article is for general information only and does not constitute legal or professional advice. Please note the law may have changed since this article was published. We do not accept responsibility or liability for any actions taken based on the information in this article.