By Jo Seery, Professional Support Lawyer
Background
Warren Augustine was employed by Data Cars Limited as a private hire driver. He worked an average of 34.8 hours per week and was found to be a part-time worker for the purposes of the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000. All drivers, regardless of how many hours they worked, were required to pay a fixed weekly “circuit fee” of £148 to access the company’s booking system.
Mr Augustine argued that the fixed fee amounted to less favourable treatment of part-time drivers because the effect of paying the fixed weekly fee meant that part-time workers were paying a higher fee per hour worked than comparable full-time drivers and therefore took home less pay per hour. The Employment Tribunal initially rejected his claim, finding that the fee was necessary for the company to earn revenue for the business and not because he was part time. Furthermore, even if it was the case that he was treated less favourably, his part-time status was not the “sole ground” for the treatment he complained of.
Mr Augustine appealed. The case turned on the statutory interpretation of regulation 5(2) of the Part-Time Workers (Prevention of Less Favourable Treatment Regulations 2000 (the Regulations)) which provides that it is unlawful to treat part-time workers less favourably than comparable full-time workers “only if–
(a) the treatment is on the ground that the worker is a part-time worker, and
(b) the treatment is not justified on objective grounds."
There have been conflicting judgments on this point and Mr Augustine’s case ultimately reached the Supreme Court which is the final word on the matter. The key question the Court had to consider was whether the right not to be treated less favourably only applies where part-time status was the sole reason for the less favourable treatment, or whether it is enough that part-time status was an “effective cause” of that treatment.
Outcome
The Supreme Court allowed the appeal. It held that it is enough to establish less favourable treatment if part-time status is an effective or substantial cause of the less favourable treatment
The Court considered that the Regulations implemented the European Part-Time Workers Directive (PTD). It found that although Clause 4.1 of the European Framework Agreement (annexed to PTD), states that part-time workers should be treated no less favourably than full-time workers “solely because” they work part time, the PTD gave member states the choice as to how to implement that protection.
The Regulations used the words “on the ground” that the worker is part time which was consistent with the equality legislation at the time and meant that a protected characteristic need only be an effective cause of the less favourable treatment. There was no reason why the Regulations should be construed as meaning that a part-time worker had to establish that the less favourable treatment was solely because they were part-time. To do so would be inconsistent with the standard approach to causation in discrimination cases and could undermine the protective purpose of the Regulations, with the result that many genuine cases of discrimination against part-time workers could be excluded.
Comments / Key takeaways
The Supreme Court’s judgment provides welcome clarification on the law. In doing so it overturns the judgment in McMenemy v Capita Business Services Ltd and makes clear that the existence of other causes of treatment, such as the demands on the business or administrative errors, does not mean that the treatment of a part-time worker is not less favourable on the ground of their part-time status.
The effect of the judgment brings the approach to part-time worker discrimination into line with broader discrimination law principles, where a protected characteristic need only be an effective cause of the treatment. However, unlike discrimination claims, the burden of proof is on the employer to identify the ground for the less favourable treatment. In light of this decision employers’ explanations as to why part-time workers are treated less favourably than full-time workers are likely to come under greater scrutiny and tribunals may have more scope for inferring a discriminatory reason.
One thing Unions may wish to do in light of the judgment is review those workplace practices which may result in part-time workers being treated less favourably. For example, where entitlement to workplace benefits is not pro-rated, how work is re-allocated or hours changed amongst part time and full time workers and examine pay structures which, like the case of Augustine, result in a part-time worker earning less per hour than a full-time worker. Another point to note is that while it should be easier to establish part time status as the reason for the less favourable treatment it is still open for an employer to argue that the less favourable treatment is justified.
Augustine v Data Cars Limited [2026] UKSC 30
