Fish tank worker with rare infection: employment ended by mutual agreement, not dismissal
A fish tank maintenance worker who contracted a rare bacterial infection from work was not unfairly dismissed – the tribunal found he agreed to end his employment after being offered a different role with lower pay.
2 min read · Last updated 19 May 2026
Case details
- #mutual-agreement
- #work-related-illness
- #mycobacterium-marinum
- #reassignment
- #holiday-pay-dispute
Key facts
- The claimant worked as a fish tank maintenance worker from September 2019 to January 2023.
- He contracted a rare bacterial infection (Mycobacterium Marinum) from work in June 2022.
- The respondent reassigned him to a pond construction role due to health and safety concerns.
- The claimant was unhappy with the new role and lower pay, and raised the possibility of redundancy.
- The tribunal found the employment ended by mutual agreement, not dismissal.
- The claimant failed to prove he was owed holiday pay on termination.
Timeline
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Employment started
Claimant began working for the respondent as a fish tank maintenance worker.
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Infected finger
Claimant saw a doctor about an infected finger, later diagnosed with Mycobacterium Marinum.
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Diagnosis
St George's Hospital diagnosed the claimant with Mycobacterium Marinum infection.
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Meeting about reassignment
Mr and Mrs Flood raised the prospect of reassigning the claimant to pond construction role.
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Sickness absence
Claimant was sick for first two working days of January; later disputed whether these were taken as holiday.
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Meeting and letter
Claimant met with Floods, unhappy with pond role; respondent sent letter referencing redundancy suggestion.
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Claimant accepted offer
Claimant texted Mrs Flood accepting 'the redundancy offer' and agreed to end employment.
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Payment received
Claimant received a sum equivalent to four weeks' pay from the respondent.
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Claim form filed
Claimant filed his claim with the employment tribunal.
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Hearing
Substantive hearing took place at London South Employment Tribunal.
The legal issue
The tribunal had to decide whether the claimant was dismissed or his employment ended by mutual agreement, and whether he was owed holiday pay on termination.
The outcome
The tribunal dismissed all claims, finding that the employment ended by mutual agreement and that no holiday pay was owed.
- The claimant contracted Mycobacterium Marinum from work in June 2022 and was reassigned to a pond construction role due to health and safety concerns.
- He was unhappy with the new role and lower pay, and suggested redundancy. After a meeting, the respondent wrote a letter referencing his suggestion, and the claimant texted accepting 'the redundancy offer'.
- The tribunal concluded this was a mutual agreement to end employment, not a dismissal. The claimant also failed to prove he was owed holiday pay for two disputed days in January 2023.
Lessons & takeaways
- If you suggest redundancy and then accept an offer to leave, a tribunal may find your employment ended by mutual agreement, not dismissal – even if you later feel pressured.
- Keep clear records of all communications about changes to your role and pay; ambiguous texts or letters can be interpreted as acceptance.
- Holiday pay claims require evidence that you actually requested and were refused holiday; simply being absent does not automatically entitle you to pay.
- Work-related illness may lead to reassignment, but if you reject the new role and propose leaving, you risk losing unfair dismissal protection.
A rare infection leads to a change of role
This case shows how a workplace illness can lead to unexpected changes in duties and pay – and how the way you respond to those changes can determine your legal rights. The claimant, a fish tank maintenance worker with three years' service, contracted a rare bacterial infection (Mycobacterium Marinum) from his work in June 2022. His employer, Glassbox Trading Limited (trading as Aquatechniques), reassigned him to a pond construction role to reduce his exposure to water, following advice from their insurer about potential health and safety claims.
The claimant was unhappy with the new role, which paid less, and raised the possibility of redundancy during a meeting in January 2023. The employer then sent a letter referencing that suggestion, and the claimant texted back accepting 'the redundancy offer' and agreeing to end his employment. He received a payment equivalent to four weeks' pay.
Why the tribunal decided it was a mutual agreement
The tribunal found that the claimant's text message clearly accepted the employer's offer to terminate the employment by mutual agreement. Even though the claimant later argued he felt he had no choice, the judge noted that he had initiated the redundancy discussion and voluntarily accepted the terms. The key lesson: when you suggest redundancy and then agree to leave, a tribunal may treat this as a consensual end to the relationship, not a dismissal – meaning you cannot claim unfair dismissal.
The claimant also failed to prove he was owed holiday pay for two days in January 2023 when he was absent. The tribunal accepted the employer's evidence that he had not booked those days as holiday, and that he had already taken all his accrued holiday.
What this means for similar claims
This case highlights the importance of clear communication when your role changes due to illness. If you are offered a different role with lower pay, you have options – but if you propose redundancy and accept a termination package, you may lose the right to claim unfair dismissal. Keep written records of all discussions, and if you feel pressured, seek advice before agreeing to leave. The outcome also shows that holiday pay claims require solid evidence that you requested and were refused holiday – simply being absent is not enough.
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