Supreme Court clarifies test for part-time worker discrimination
The Supreme Court handed down its decision in Augustine v Data Cars Ltd on 12 August 2026. The case concerns the protection of part-time workers from less favourable treatment under regulation 5 of the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000.
The Supreme Court considered whether a part-time worker must prove that their part-time status was the sole reason for the less favourable treatment, or whether it is sufficient for part-time status to have been an effective cause of that treatment.
The Supreme Court held that effective cause is sufficient. Part-time status does not have to be the sole cause.
Background
Mr Augustine worked part-time for Data Cars Ltd as a private-hire driver in 2016, working an average of 34.8 hours per week. A full-time comparator worked an average of 90 hours per week. Data Cars charged its drivers a fixed £148 weekly "circuit fee" for access to its booking/dispatch system, regardless of the number of hours worked. He brought a claim under the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000.
The Employment Tribunal initially found that there was no less favourable treatment simply because all drivers paid the same fee. The EAT overturned that finding, applying the pro rata principle. The Supreme Court proceeded on the basis that the fixed fee did amount to less favourable treatment. It found that the law protects part-time workers if their status is an effective cause of the disadvantage. It does not matter if the employer also had other business reasons for the rule.
Employers who previously defended claims on the basis that there were other reasons for the treatment will need to consider whether:
- part-time status was an effective cause of the less favourable treatment; and
- the less favourable treatment can be objectively justified.
For further information or to discuss how this may affect your business, please get in touch with KKnox@ortolan.com or jjones@ortolan.com
Posted on 09/20/2026 by Ortolan
