Mrs C Mason v Wilko Limited AT A FINAL HEARING — 2023

Mrs Mason exercised her statutory right to opt out of Sunday working in January 2016. The tribunal found that her underlying contract remained the standard 5-out-of-7 contract and that the opt-out did not itself vary the contract so as to require her Sunday hours to be redistributed across Monday to Saturday. It accepted that, where business needs allowed, the respondent aimed to roster opted-out staff away from Sundays, but that this was never an enforceable contractual entitlement.

The tribunal found that the position changed in late 2018 when the Sutton store came under greater operational pressure and the respondent updated its Sunday working guidance after collective consultation with the GMB and individual meetings with staff. From November 2018 Mrs Mason was rostered for some Sundays, did not work those shifts because of her opt-out, and was not paid for the hours not worked. The tribunal rejected her case that this amounted to a contractual variation agreed with Mr Elleston in 2016, finding instead that the earlier six-day rostering reflected the respondent's non-contractual aim of minimising disruption where possible.

The tribunal also rejected the allegation that the respondent's conduct, including the 2018 grievance handling, the 2021 grievance decision by Mr Broughton, the 2021 appeal decision by Ms Marshall, and the Project Horizon restructuring, amounted to a repudiatory breach of trust and confidence. It found that the grievance about Sunday working had been answered in writing in November 2018, that no further 2018 grievance to the employer was proven, and that the 2021 grievance and appeal were considered reasonably. Although Mr Broughton partly upheld the grievance on the absence of a structured overtime system, the tribunal found the Sunday working guidance and the later rostering decisions were driven by genuine business needs and were applied consistently.

The tribunal dismissed the constructive unfair dismissal claim, including the alternative automatic unfair dismissal case under s.104 ERA 1996, because none of the alleged conduct was found to have been done for the reason that Mrs Mason had asserted infringement of her statutory right to opt out of Sunday working. It also dismissed the breach of contract claim, holding that there was no notice-based wrongful dismissal claim on the facts and that any implied-term claim would fail with the unfair dismissal claim. The unlawful deduction from wages claim also failed because the contract still permitted Sunday rostering after the opt-out, so the pay she received on weeks when she did not work Sunday was the amount properly payable.