When “one-size-fits-all” policies disadvantage part-time staff: Key lessons for employers from the recent Supreme Court decision in Augustine
Tuesday 25th August 2026
The Supreme Court’s decision in Augustine v Data Cars Ltd, confirms that, for a part-time worker discrimination claim to succeed, part-time status only needs to be an effective cause of the less favourable treatment rather than the sole reason for it.
The decision lowers the threshold for claims of this nature and is a timely reminder for employers to review policies and practices that may unintentionally disadvantage part-time staff.
The facts
The Claimant, Mr Augustine, was a part-time private hire driver employed by Data Cars Ltd (the Respondent). All of the Respondent’s drivers regardless of whether they worked full or part-time were charged a weekly ‘circuit fee’ of £148 to access its booking system.
Mr Augustine brought a claim to the Employment Tribunal (ET) and argued that because he paid a much higher fee per hour than a comparable full-time driver, this amounted to unfavourable treatment because he worked part-time.
The Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 (PTWR) protect part-time workers from being treated less favourably than comparable full-time colleagues, where the treatment is because they work part-time and cannot be objectively justified.
The ET’s decision
The ET rejected Mr Augustine’s claim and acknowledged whilst both part-time and full-time workers were charged the same circuit fee and may have a disproportionate effect, the fee was not charged solely because Mr Augustine was a part-time worker.
Mr Augustine appealed to the Employment Appeal Tribunal (EAT).
EAT & Court of Appeal
The EAT rejected Mr Augustine’s appeal as it was bound by case law from an earlier Scottish case (McMenemy v Capita Business Services Ltd), albeit considered, McMenemy was wrongly decided.
Mr Augustine then appealed to the Court of Appeal, and because there had been issues with interpretation of previous case law on this matter, permission to appeal to the Supreme Court was granted so clarity on this issue across the UK could be provided.
Supreme Court’s judgment
The Supreme Court unanimously allowed the appeal and found that part-time status only needs to be an effective cause of the less favourable treatment. It does not need to be the sole or exclusive reason for the employer’s decision.
Case comment
This case lowers the threshold for bringing claims of this nature. Workers now only need to show that their part-time status contributed to the disadvantage, rather than proving it was the sole cause.
The ruling does not mean every difference in treatment is unlawful and the PTWR still permit that treatment can be objectively justified via a legitimate business aim.
Employers should be ready to explain why a one-size-fits-all approach was necessary and whether a less disadvantageous alternative was available.
What should employers do next?
This case provides a good opportunity for employers to review arrangements affecting their part-time staff, such as:
- Pay and Bonuses – Check that salary, bonuses, pay increases and allowances are calculated on a pro-rata basis where appropriate. Employers should record the reasons for any departure and ensure mangers apply the approach consistently.
- Bank Holidays – Check how bank holidays and annual leave are calculated for different working patterns. A fixed full-time assumption can produce an unintended shortfall or an unfair benefit for part-time staff.
- Keep an evidence trail – identify the legitimate aim, assess its impact and consider alternatives. Identical treatment is not always equal treatment. The aim is not to avoid consistency, but to ensure policies are designed with part-time workers in mind and that any resulting differences can be justified.
If you would like support reviewing your policies and practices, assessing potential risks, or discussing the implications of this decision for your organisation, please contact a member of our Employment Team.
