Polkey v AE Dayton Services
Procedural fairness & the Polkey reduction
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What’s the difference between Polkey and contributory fault?
Polkey addresses procedure (would dismissal have happened if procedure had been fair?). Contributory fault addresses your conduct (did you contribute to the dismissal?). Both can reduce compensation but apply to different questions.
Does Polkey apply in discrimination cases?
No. Polkey is an unfair dismissal doctrine. Discrimination claims don’t use Polkey — if you’re dismissed for a discriminatory reason under the Equality Act 2010, compensation isn’t reduced by Polkey.
What if the employer makes no Polkey argument?
If the employer doesn’t raise Polkey, the tribunal won’t apply it. The burden is on the employer to prove the reduction — if they don’t address it, you receive full compensation.
Does Polkey apply to redundancy cases?
Yes. If a redundancy is procedurally unfair (inadequate consultation, unfair selection), Polkey applies. The tribunal asks whether dismissal would still have happened with proper consultation, and the percentage reduction follows.
Is it possible for a Polkey reduction to be 100%?
Rarely. A 100% reduction would mean dismissal was certain even with a fair procedure. Tribunals are reluctant to go that high — reductions typically range from 20% to 80%.
Polkey v AE Dayton Services
Last updated: April 2026
Procedural failures make a dismissal unfair even if dismissal would have been the outcome regardless — but compensation is adjusted to reflect that inevitability.
Mr Polkey was a van driver made redundant without consultation. His employer argued a proper redundancy consultation would have made no difference to the outcome — he would have been dismissed anyway. The Court of Appeal agreed with the employer. The House of Lords reversed this, restoring the proper approach to procedural fairness.
What the House of Lords decided
Lord Bridge: it is almost always wrong to ask "would a proper procedure have made any difference?" when deciding if a dismissal was unfair. It is almost always unfair to dismiss without following a fair procedure. The question of inevitability goes to compensation, not liability.
This separated two distinct questions: (1) Is the dismissal unfair? (answer: yes, if procedure was defective); (2) What should compensation be? (answer: adjusted by the chance dismissal would have happened anyway). This structure protects claimants from employers who cut corners and argue "it wouldn't have mattered."
Before and after Polkey
employers sometimes escaped liability by showing consultation would have been futile. The case turned into a counterfactual: what would the employer have done if they'd followed procedure?
dismissal without procedure = unfair dismissal. Full stop. But compensation is reduced proportionally to the chance of dismissal anyway. This means you win liability but may not recover full compensation.
The Polkey reduction in practice
The tribunal assesses: what was the chance of dismissal following a fair procedure? This is expressed as a percentage. Examples:
- the employee would have been dismissed fairly anyway with 80% probability — so compensation is reduced by 80% from that point.
- genuinely uncertain — compensation is halved.
- procedure was so defective there's no realistic chance dismissal would have happened anyway — full compensation
It can be difficult for employers to establish a high Polkey reduction. They need to provide concrete evidence of what they would have done, not speculation. "We would have dismissed them anyway" without supporting evidence often fails.
How to resist a Polkey reduction
Key arguments include:
- Other outcomes possible:
- redeployment, different role, improvement plan — dismissal was not inevitable
- Investigation was so poor:
- you can't know what it would have shown — the employer can't rely on outcomes from a defective investigation
- You were denied the chance to respond:
- with key information or witnesses, the outcome might have been different
- others in similar positions were not dismissed — suggests dismissal was not inevitable
- Employer's own words:
- if they said at the time "this isn't gross misconduct" or "we'll help with redeployment," use those against them
Key limitation: Polkey applies to compensation, not liability
Polkey cannot be used to argue the dismissal was fair. If the procedure was defective, the dismissal is unfair. Full stop. Polkey only affects how much compensation you receive, not whether the dismissal was wrongful.
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Polkey v AE Dayton Services Ltd [1987] UKHL 8 (BAILII)
Questions people ask
What is the difference between Polkey and contributory fault?
Polkey addresses procedure: "If the procedure had been fair, would dismissal have happened?" Contributory fault addresses the employee's conduct: "Did the employee contribute to the dismissal?" Both can reduce compensation, but they apply to different questions. You can win liability but have both Polkey and contributory fault reductions applied to compensation.
Does Polkey apply in discrimination cases?
No. Polkey is an unfair dismissal doctrine. Discrimination claims don't use Polkey. If you're dismissed for a discriminatory reason, the dismissal is automatically unfair under the Equality Act 2010, and you don't reduce compensation by Polkey. (Contributory fault can still apply.)
What if the employer makes no Polkey argument?
If the employer doesn't raise Polkey, the tribunal won't apply it. You receive full compensation for the unfair dismissal. The burden is on the employer to prove the Polkey reduction. If they don't address it, you benefit.
Does Polkey apply to redundancy cases?
Yes. If a redundancy dismissal is procedurally unfair (inadequate consultation, unfair selection criteria), Polkey applies. The tribunal asks: if proper consultation had happened, would the employee still have been dismissed? The percentage reduction follows.
Is it possible for a Polkey reduction to be 100%?
Rarely. A 100% Polkey reduction would mean the employee would certainly have been dismissed following a fair procedure. Tribunals are reluctant to go that high because it essentially says procedure didn't matter. Polkey reductions typically range from 20% to 80%, depending on how inevitable dismissal would have been.
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Polkey v AE Dayton [1987]
Employment Rights Act 1996