The Supreme Court has clarified the causation test for claims of less favourable treatment under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 (the Regulations).
Background
The Regulations provide that a part-time worker has the right not to be treated less favourably than a comparable full-time worker where:
- The treatment is "on the ground that" the worker is a part-time worker, and
- The treatment cannot be objectively justified
Earlier cases had held that the words “on the ground that” meant that the claimant's part-time status had to be the sole cause of the less favourable treatment in order for a claim to succeed.
The case of Augustine v Data Cars Ltd concerned a part-time taxi driver. His employer required all drivers to pay the same fixed weekly charge to access their booking system regardless of how many hours they actually worked, which therefore represented a greater cost per hour for part-time workers. It was accepted that this was less favourable treatment of part-time workers when compared to full time workers.
Mr Augustine's claim had proceeded through the employment tribunal, Employment Appeal Tribunal and Court of Appeal and had been unsuccessful at each stage as his employer had been able to show that his status as a part-time worker was not the sole cause of the less favourable treatment.
The key question before the Supreme Court was therefore if the previous interpretation of the words "on the ground that" was correct – in order for the claim to succeed did the claimant's part-time worker status need to be the sole reason for the less favourable treatment or did it just need to be an effective cause?
Supreme Court decision
The Supreme Court held that the previous decisions were incorrect and that part-time status need only be an effective cause of the treatment i.e. have a significant or substantial influence on it. Part-time status did not have to be the main ground, still less the sole ground or reason for the treatment.
In reaching its decision, the Supreme Court emphasised that by the time the Regulations were introduced in 2000, the phrase "on the ground that" had a well-established meaning in discrimination law that required the relevant protected characteristic only to be an effective cause of the treatment complained of. It was therefore reasonable to assume that the drafters of the Regulations had chosen that phrase with that meaning in mind. It also considered that it would be surprising if protections for part-time workers were subject to a materially different and more restrictive causation test than protections against other forms of discrimination.
What does this mean for employers?
The decision makes it easier for employees to bring a successful claim under the Regulations. Employers will no longer be able to defeat a claim simply by demonstrating that something other than the claimant's part-time status contributed to the treatment complained of.
However, it will still be possible to defend claims by demonstrating that the less favourable treatment was objectively justified. The Supreme Court also noted that the existence of other contributing factors may be relevant to the amount of compensation that successful claimants are awarded.
Organisations should nonetheless give careful thought to whether any of their arrangements and practices disadvantage their part-time workers compared to those who are full time and, if so, whether the difference in treatment can be justified.
