The Supreme Court has handed down its judgment in Augustine v Data Cars Limited, resolving a longstanding uncertainty over the causation test under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000.
The decision makes clear that a part-time worker does not need to prove that their part-time status was the sole reason for less favourable treatment. It is sufficient to show that being a part-time worker was an effective cause of the treatment.
For employers, this lowers the threshold for bringing a claim and places greater importance on whether any difference in treatment can be objectively justified.
The case concerned Mr Augustine, a private hire driver engaged by Data Cars Limited. Drivers had to pay a weekly £148 “circuit fee” to access the company's booking system. Mr Augustine worked fewer hours than typical full-time drivers. He argued that applying the same fixed weekly fee to him resulted in less favourable treatment because, when considered by reference to the hours worked, he effectively paid more per hour than a full-time comparator.
The Employment Tribunal rejected his claim, finding that the treatment was not because he was a part-time worker, or alternatively that his part-time status was not the sole cause.
The case later progressed through the Employment Appeal Tribunal and Court of Appeal before reaching the Supreme Court.
The Supreme Court rejected the requirement for part-time status to be the sole cause of the less favourable treatment. Instead, the Court confirmed that the proper test is whether the worker's part-time status was an effective cause of the treatment. This means that a claim will not necessarily fail simply because there were other reasons for the employer's decision. Part-time status only needs to have been one of the operative causes. The judgment therefore brings the causation test under the Part-time Workers Regulations closer to the approach generally applied in discrimination law.
The practical consequence is significant: employers will have less scope to defeat claims by arguing that a particular decision was made for several reasons and that part-time status was not the exclusive reason.
The focus now shifts to justification. The decision does not mean that every difference in treatment of part-time workers will be unlawful. The Regulations allow less favourable treatment where it can be objectively justified.
So, once a part-time worker establishes that their part-time status was an effective cause of the treatment, the employer is likely to need to focus on whether the treatment can be objectively justified. This makes it particularly important for employers to be able to prove a legitimate business rationale for any arrangements that operate differently, or less favourably, for part-time workers.
Employers should consider reviewing their arrangements for part-time workers, particularly in the following key areas:
Part-time workers should generally receive the same rate of pay as comparable full-time workers. Employers should also take care when applying bonus schemes, pay increases and discretionary awards.
Benefits should generally be provided on a pro rata basis where appropriate. Where a benefit cannot sensibly be pro-rated — such as certain insurance arrangements, company cars or staff discounts — employers should consider whether providing the benefit in full is appropriate or whether there is sound objective justification for an alternative approach.
Employers should review any flat-rate fees or charges that apply regardless of hours worked. The Augustine decision shows the potential risks where a fixed cost has a disproportionate impact on part-time workers.
Employers should review how bank holiday entitlement is calculated for part-time workers, particularly those who do not work Mondays or Fridays. A pro rata entitlement will often be the lower-risk approach.
Part-time worker discrimination can arise in less obvious situations, including weekend working requirements, access to opportunities, working arrangements and return-to-office policies.
The key message from Augustine is that employers should be cautious about relying on technical arguments concerning causation.
Where part-time status has played a role in less favourable treatment, the employer may now need to prove that the treatment was objectively justified.
Employers should therefore consider whether their policies and practices work fairly for part-time workers and, where different treatment is necessary, ensure that the business rationale is clearly found and documented.
The judgment does not prevent employers from treating full-time and part-time workers differently where there is a legitimate and objectively justifiable reason. However, employers should expect greater scrutiny of the reasons for any difference in treatment.
For employers, now is a sensible time to review part-time working arrangements, particularly where fixed costs, benefits, working patterns or discretionary decisions may produce a disproportionate outcome for part-time workers.
If you need any further advice and help, please do not hesitate to contact the Quest HR Advice Line on 01455 852 028.
