In Essop, the Supreme Court restored what was previously understood to be the law on indirect discrimination. The claimant need not establish the reason for the relevant disadvantage.
Controversially, in 2015 the Court of Appeal had held that a claimant for indirect discrimination must show why the provision, criterion or practice (PCP) disadvantages the relevant group, and that the disadvantage suffered by the particular claimant was for the same reason. This ran counter to previous understanding of the law, and there was concern that indirect discrimination would no longer offer the protection it was intended to give.
The Supreme Court has now reinstated the previously understood position. In Home Office (UK Border Agency) v Essop, www.bailii.org/uk/cases/UKSC/2017/27.html statistics showed that BME (black and minority ethnic) and older candidates were less likely to pass an exam for promotion, but it was not known why. The Supreme Court held that an indirect discrimination claim could succeed even if the claimant could not establish the reason for the disadvantage.
More: Indirect discrimination.