The Religion or Belief Regulations (now part of the Equality Act) state that employers cannot impose a provision, criterion or practice (PCP) which discriminates against a worker on the basis of their religion or belief, unless they can justify it. In Mba v The Mayor and Burgesses of the London Borough of Merton, the Court of Appeal held that the Council’s requirement for Ms Mba to work on Sunday was a proportionate means of achieving a legitimate aim. 

Basic facts

Ms Mba, a Christian, worked in a children’s home providing short, residential breaks for children with serious disabilities and complex care needs. Three members of staff, who worked a rota system covering seven days a week, were required to be on duty at any one time.

For the first two years, the council managed to accommodate Ms Mba’s request not to work on Sundays. However, in 2009, it said she had to start working a rota that included Sundays. She lodged a grievance which was unsuccessful and as she did not work any of the Sundays for which she had been rostered, she was given a final written warning in early 2010.

When her appeal failed, she resigned at the end of May 2010 and claimed indirect discrimination on the basis that her employer had applied a PCP which discriminated against her as a Christian. 

Tribunal and EAT decision

The tribunal identified the PCP as the requirement that staff must work their rostered Sunday shifts. Although this impacted on Ms Mba’s genuinely and deeply held religious belief that Sunday should be a day of rest, the tribunal held that this was not a core component of the Christian faith. The PCP was therefore a proportionate means of facilitating the effective running of the home by the Council.

In dismissing Ms Mba’s appeal, the EAT said that the tribunal’s comment that resting on Sunday was not a “core component” of Christianity reflected the evidence of an Anglican bishop that not all Christians felt unable to work on a Sunday.The EAT concluded that the tribunal was right to find that the Council had a number of legitimate aims and that the PCP was a proportionate means of achieving them.

Decision of Court of Appeal

Although the Court of Appeal upheld the tribunal’s decision, it disagreed with the finding that working on Sundays was not a “core component” of the Christian faith (but for different reasons to the tribunal). Instead, one of the judges held that it was not necessary to establish whether most Christians would be put at a particular disadvantage, as that would open the door to a quantitative test that was far too wide.

Given that it was unacceptable for some Christians (including Ms Mba) to work on a Sunday, the tribunal should have found that applying this PCP put her at a disadvantage compared with other people who did not share her beliefs. Having done that, it should then have gone on to look at whether the Council could show "a proportionate means of achieving a legitimate aim".

The other two judges held that, as it did not matter whether her views were widely shared or whether they constituted a core belief of any particular religion, the tribunal was wrong to refer to this factor as one that helped the employer.

Despite the error in law, all three judges agreed that the tribunal’s decision was "plainly and unarguably right". Once the Council had established that it had no viable or practicable alternative way of running the home effectively, “there was only ever going to be one outcome to this case. The legal error can have made no difference”.



Ms Mba produced evidence that some Christians as part of their religious belief observe the Sabbath. She did not have to prove that all or most of them did and the judges made it clear that tribunals should not get involved in doctrinal arguments. This case also demonstrates that it is not that difficult for employers to show that there is a reason for the treatment that outweighs the discriminatory impact.