More than a quarter of Marks & Spencer investors could this week abstain or vote against Sir Stuart Rose’s elevation to executive chairman.

At Wednesday’s AGM, Rose faces one of the largest shareholder revolts in recent history, with many expected to abstain as a mark of unease or oppose the decision altogether.

Rose has come up against a barrage of criticism since his announcement in March to elevate himself to the dual role of chief executive and executive chairman. Both the Association of British Insurers and corporate governance research group Pirc have raised concerns over the decision.

The shock profit warning issued by M&S last week – which sent its share price plummeting 32 per cent – has further unsettled the retailer’s shareholders.