No, says the EAT in Wright v North Ayrshire Council.
It is sufficient that the repudiatory breach "played a part in the dismissal" in accordance with CA authority in Nottingham County Council v Meikle.
The Claimant was a care at home assistant until she resigned. The first instance tribunal found, inter alia, that the Claimant's three grievances had not been properly answered. The EAT was satisfied that the tribunal considered the contractual breaches serious enough to constitute a repudiatory breach/es.
However, the tribunal dismissed the claim on the basis that the Claimant's caring responsibilities for her partner who had recently suffered a stroke were "the effective cause" of her resignation rather than her employer's conduct, applying the EAT case Jones v Sirl.
The EAT ruled that the first instance tribunal misinterpreted the meaning of the "effective cause" criterion as clarified by the CA in Meikle and the EAT case Abbey Cars (West Horndon) Ltd v Ford. Rather than being 'the' effective cause it is enough that the repudiatory breach was 'an' effective cause, with no requirement that it be the most important cause. The extent of the role played by the breach will be taken account of in calculating the compensation award.