Unfair dismissal (constructive) — definition anchored to a real case: Ms Tracey v Acas (2023)

Constructive unfair dismissal definition — explained through a real Acas case. Sometimes you’re not marched out the door; instead, the ground gives way under your feet. Pay and holiday records don’t add up. You raise it—again and again—but nothing gets fixed. Confidence drains away until staying becomes impossible. That’s constructive unfair dismissal definition: you resign because your employer’s serious breach leaves you no real choice.

In Ms Tracey v Acas (2023), the Tribunal found just that. Over months, Acas miscalculated/recorded holiday, sent conflicting messages, and failed to resolve clear grievances. A final phone call became the last straw, and Ms Tracey resigned. The Tribunal held the resignation was a response to the employer’s breaches — so the dismissal was unfair, with holiday pay awarded too. What is important: meeting the definition of constructive dismissal, the tribunal takes into account all circumstances.

This article turns that judgment into practical steps you can use: how to pin down your holiday entitlement in writing, how to run a focused grievance (not a scattergun), how to spot a last straw, and how to frame your ET1 if you have to leave. If even Acas can get this wrong, any employer can—so let’s make sure you don’t let a good case sink for want of clarity, records, or timing.

Note: This article isn’t “anti-Acas”; it’s a reminder that record-keeping, clarity and prompt grievance handling are legal essentials. Even Acas got this wrong here; any employer can. If you’re stuck in a holiday/pay maze, use Acas for conciliation, but get tailored legal advice on calculation, deadlines and exit strategy.

This is our series on unfair dismissal definitions—real case scenarios, real judgments, and real issues we face.

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Unfair dismissal definition from a real case scenario with UDO 

What you’ll learn in this article

• Case snapshot (who, when, what went wrong)

• Constructive unfair dismissal: the definition in one paragraph

• Why the Tribunal said it was unfair (the building blocks)

• Before you resign: get the numbers straight (holiday/pay checklist)

• Templates to use now (clarity requests you can paste)

• Grievance that works (keep it focused, tie it to evidence)

• The “last straw”: timing, wording, and what to say

• ET1 headings you can lift (constructive unfair + holiday pay)

• ET1 short-form wording (ready to adapt)

• Evidence checklist (what to attach and why)

• Final quick tips (don’t miss deadlines; don’t go it alone)

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Case snapshot (who, when, what went wrong)

Ms Tracey v Acas — why the Tribunal found constructive unfair dismissal. In this case, the Tribunal said Ms Tracey was constructively unfairly dismissed because the employer’s conduct undermined trust to the point she had no real choice but to resign. Over many months, holiday entitlement was miscalculated and badly recorded for her term-time/part-time pattern; payroll gave conflicting answers (at times even hinting at overpayment), and despite meetings and promises, the issue was not resolved. That rolling uncertainty—no reliable records, shifting figures, and an unresolved grievance—was the ongoing breach. A final phone call where Acas still couldn’t confirm a clear, final position became the last straw; she resigned immediately after. The Tribunal held that resignation was a direct response to the employer’s breaches, so the dismissal was unfair, and holiday pay was awarded as well.

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Constructive unfair dismissal: the definition in one paragraph

Constructive dismissal is where you resign in response to your employer’s fundamental breach of contract (usually the implied term of trust and confidence) and you don’t wait so long that you’re seen to accept the breach. In Tracey, the breach was built from persistent holiday/pay errors, no reliable records, conflicting answers, and unresolved grievances; a final call was the last straw, and she resigned promptly.

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Why the Tribunal said it was unfair (the building blocks)

1. No proper records / wrong configuration: the HR system wasn’t set up for her pattern; figures moved around.

2. Contradictory information: payroll alternated between “you owe us” and “we owe you” without landing a final answer.

3. Unresolved grievance over time: meetings and promises didn’t produce a clear, stable figure.

4. Last straw: a fresh conversation confirmed it still wasn’t fixed, reviving earlier breaches and justifying resignation.

Takeaway: Ongoing uncertainty + failure to resolve a focused grievance can destroy trust; a fresh incident can be the last straw.

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Before you resign: get the numbers straight (holiday/pay checklist)

Ask for all of this in one written request:

• Your holiday entitlement (hours) and the calculation method for your actual pattern (term-time/part-time).

• How bank holidays/privilege days are treated.

• Your leave record for the last 24 months (screenshots fine).

• The policy/procedure relied on.

• Confirmation there’ll be no deduction/clawback unless a specific error is set out with calculations.

Why: If the employer can’t provide a clear, final answer after multiple asks, that supports breach and shows why confidence has gone.

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Templates to use now (clarity requests you can paste)

Holiday clarity (send to HR/payroll):

Please confirm my annual leave entitlement (in hours) and the calculation used for my term-time/part-time pattern, including treatment of bank holidays and any privilege days. Please also provide my leave record for the last 24 months and the policy relied on. I would be grateful for a single, final figure in writing with workings.

If ‘overpayment’ is raised:

Please set out the sum, period, and calculation you rely on. I dispute liability pending disclosure. Any deduction without my agreement will be treated as unauthorised.

If figures keep changing:

Given the conflicting figures so far, please provide one final written figure with a step-by-step calculation for my pattern, and confirm whether any clawback is proposed (with workings).

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Grievance that works (keep it focused, tie it to evidence)

Title: Holiday entitlement & pay — failure to calculate and resolveBody (bullet the essentials):

• Dates of wrong/contradictory messages and any overpayment hints.

• Dates of promises to fix (e.g., “final figure by [date]”).

• What’s still missing (final figure, corrected record, assurance on deductions).

• Request: a clear written figure with workings and corrected records by [deadline], plus an appeal right if not resolved.

Tip: Keep it tight and evidenced. A neat, focused grievance shows the problem is fixable—and records failure to fix.

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The “last straw”: timing, wording, and what to say

A last straw is a new incident that revives earlier breaches and tips you over the edge.

Checklist before resigning:

• Identify the fresh trigger (call/meeting/email showing it’s still not fixed).

• Write that the situation is untenable and ask for urgent resolution by a short, specific deadline.

• If you resign, do it promptly and say you resign in response to the breaches and the last straw.

Short wording for your letter/email:

I resign with immediate effect in response to your fundamental breach: persistent failure to calculate and record my holiday correctly, conflicting information, and unresolved grievance, culminating in a last straw on [date].

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ET1 headings you can lift (constructive unfair + holiday pay)

• Constructive unfair dismissal (breach of trust/confidence): persistent failure to calculate/record leave correctly; contradictory information; unresolved grievance; last straw on [date]; resignation [date].

• Holiday pay: underpayment of statutory/privilege/bank-holiday entitlement → £[x] due (show working).

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ET1 short-form wording (ready to adapt)

I resigned on [date] in response to the Respondent’s repudiatory breach: persistent failure to calculate and record my holiday correctly, contradictory/wrong advice, and unresolved grievances, culminating in a last straw on [date]. I claim constructive unfair dismissal and holiday pay of £[x].

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Evidence checklist (what to attach and why)

• Email trail showing conflicting figures and promises to fix (proves uncertainty + attempts to resolve).

• HR system screenshots (leave/HR records) showing gaps/changes.

• Grievance letters, minutes, outcomes, and appeal.

• Resignation letter referencing breach/last straw.

• Your own calculation (simple spreadsheet) showing what you’re owed.

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Final quick tips (don’t miss deadlines; don’t go it alone)

• Keep everything in writing; ask for a final figure with workings.

• Log every change of position with dates.

• Use a focused grievance; don’t scattergun.

• If you hit a last straw, act promptly.

• Start Early Conciliation and get tailored legal advice on timings, sums, and exit wording.

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Have a question or something to add?

Spot something similar in your case? Drop a comment or ask a question below — I read and reply.If you want tailored pointers, include (briefly): your work pattern (full-time/part-time/term-time), the dates the issue started, what records/policies you’ve been given, and what you’ve already asked for in writing.

Not ready to post publicly? Ask your question without names or upload a redacted snippet — I’ll still help.