Part-Time Workers: Update 

What amounts to less favourable treatment of a part-time worker?

Prior to the recent Supreme Court decision in Augustine v Data Cars Ltd [2026] UKSC 30, it was unclear whether part-time work must be the sole cause or merely one effective cause among others for discrimination to have occurred. The Supreme Court has now decided that for discrimination to occur part-time work does not need to be the sole cause.

The facts 

The claimant, Mr Augustine, drove on a part-time basis for Data Cars Ltd. He was required to pay a “circuit fee” of £148 per week, which applied to all drivers, regardless of part-time status. He argued that this amounted to less favourable treatment in the absence of a pro rata approach to the Circuit Fee.

The decision 

The Employment Tribunal initially decided that part-time status had to be the sole cause of the circuit fee for the claim to succeed and thus the claim initially failed because the Tribunal found that the circuit fee was standard practice in the industry and that this was the cause.

After proceeding through the appellate courts, the Supreme Court decided that the phrase “on the ground that” in regulation 5(2)(a) of the Part Time Worker Regulations is consistent with that used in other areas of discrimination law such that part-time work need only be the effective cause.

The importance of this decision to Mr Augistine’s claim is that the absence of a pro rata principle being applied to the circuit fee clearly places him at a disadvantage due to him working less hours than full time drivers. The fact that the fee is standard practice in the industry does not prevent a claim for discrimination on the grounds of part-time worker status following the Supreme Court decision.

It is important to recognise that employers do have a justification defence available for treating part-time workers less favourably. It may be proportionate in some cases to treat a part-time worker less favourably. For example, if an employer requires a degree of personal contact each week it could be proportionate to permit some home working for full-time staff while refusing it to part-time staff depending on the circumstances. It is unlikely that standard practice within an industry would justify less favourable treatment by itself.

Practical lessons for employers

This decision provides much needed clarity to employers and employees. Employers should review any policies impacting part-time workers to ensure compliance with the law as clarified by the Supreme Court. If any less favourable treatment is occurring the employer should consider if this is justified in the circumstances.

(September 2026)