Can part-time workers claim if their part-time status is only one reason for less favourable treatment?

What were the facts of the case?

In Augustine v Data Cars Limited, the claimant was a part-time private hire driver. All drivers were charged a fixed weekly "circuit fee" to access the respondent's booking system, regardless of whether they worked full or part-time.

The claimant argued that this amounted to less favourable treatment contrary to the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 (Regulations) because there was less favourable treatment than if the fee had been applied on a pro-rata basis.

The Tribunal dismissed the claim, finding that whilst there was less favourable treatment, the claimant's part-time status was not the "sole ground" for the treatment. It found that the reason for charging the circuit fee was that this was standard practice in the industry, rather than because the claimant worked fewer hours.

Both the Employment Appeal Tribunal (EAT) and the majority of the Court of Appeal agreed that the tribunal had erred in applying a sole ground test but considered themselves bound by an earlier Scottish decision which required that approach. The Court of Appeal granted permission to appeal to the Supreme Court.

What did the Supreme Court decide?

The Supreme Court unanimously allowed the appeal. It held that the correct test is whether a worker's part-time status was an "effective cause" of the less favourable treatment. It does not need to be the sole cause.

The Regulations give part-time workers the right not to be treated less favourably than comparable full-time workers where the treatment is "on the ground that" the worker is part-time and the treatment cannot be objectively justified.

The Supreme Court held that the phrase "on the ground that" has an established meaning in discrimination law. If the prohibited ground had a significant or substantial influence on, or was an effective cause of, the treatment, that is sufficient. It does not have to be the main ground, still less the sole ground. Although the Regulations implement an EU Directive which uses the words "solely because", the Supreme Court held that this narrower wording did not need to be read into the domestic Regulations.

Learning points for employers

The decision makes clear that employers cannot defend a claim simply by showing that part-time status was not the only reason for the treatment complained of.

The existence of other causes may still be important. The Supreme Court confirmed that they may be relevant when considering whether the treatment can be objectively justified or when determining the amount of compensation. However, they do not prevent the right under the Regulations from arising in the first place.

This is particularly relevant where arrangements which appear to treat full-time and part-time workers in the same way have a less favourable effect on part-time workers. Fixed fees, flat-rate deductions or uniform thresholds may warrant particular consideration where they are applied without adjustment for hours worked.

For more information or advice, please get in touch with Georgia Blesson in our Employment team.