Co-op's chief executive Shirine Khoury-Haq will step down on March 29 after seven years leading the UK grocery chain, as the company grapples with mounting costs from last year's cyber attack. Board director Kate Allum will serve as interim CEO while Co-op searches for a permanent replacement.

The cyber attack last April forced Co-op to shut down systems, resulting in empty shelves across its 2,300 UK stores and pushing the company into the red. The group now estimates the total cost at £285 million in lost turnover, up from previous guidance of £206 million. Profitability took a £107 million hit, with an additional £21 million in incremental costs.

Co-op stated the recovery strategy requires leadership beyond Khoury-Haq's intended tenure, signaling the scale of the challenge ahead. The timing coincides with BBC reports alleging senior managers complained about a "toxic culture" at executive level, though Co-op's lawyers disputed these claims. The cyber attack's financial impact and leadership transition come as the cooperative faces pressure to restore operations and rebuild stakeholder confidence.