A third key shareholder group has called for Morrisons chairman Sir Ken Morrison to stand down.

The Pensions Investment Research Consultants (PIRC) yesterday called on investors to oppose Sir Ken’s re-election at the groups annual meeting next week.

PIRC said that it regarded Sir Ken as a “de facto chairman and chief executive”.

Last week two key shareholder groups - the National Association of Pension Funds and the Association of British Insurers (ABI) - called for Morrison to step down after the group issued a surprise profit warning.

The ABI said that it had “serious concerns about corporate governance standards in the company”, while The National Association of Pension Funds urged Morrisons shareholders to vote against re-electing Morrison.

Meanwhile, speculation grows over the identity of Morrison’s new chief executive for whom the group is currently searching.

Media reports suggest that Archie Norman, former chairman and chief executive of Asda, could be a prime target.