PIRC, the corporate governance watchdog, is calling for Marks & Spencer shareholders to vote against the appointment of Sir Stuart Rose as chairman at the retailer's AGM next month.
The announcement of the intended promotion of M&S chief executive Sir Stuart Rose to the dual role of executive chairman and chief executive earlier this year, was in breach of corporate governance best practice and sparked a row with shareholders.
M&S has since announced a series of concessions to shareholders but the row has rumbled on.
PIRC, in guidance sent to it members yesterday, said it made its recommendation "reluctantly".
It wrote: "Combining the roles of chief executive and chairman represents a dangerous concentration of power that is potentially detrimental to board balance, effective debate and board appraisal."
It added: "We do not consider the circumstances, nor the company’s rationale, to be sufficient to warrant the move."