Sir Richard Greenbury, the former chief executive of Marks & Spencer, has accused shareholder groups of conducting a “vendetta” against current boss Sir Stuart Rose (pictured).

He slammed the shareholders for their “vindictive” attitude and said that the executive chairman should be allowed to get on with the job of running the retailer.

"I feel that this continued attacking is irrelevant to the point of being vindictive,” he told The Sunday Telegraph. “Rose has done an excellent job after six years of decline under three failed chief executives. This is the worst recession since the early 1990s and this is not the time to rock the boat and fiddle and piddle around about what someone's job title is.”

Shareholders are expected to call for the appointment of an independent chairman at a shareholder meeting on Wednesday.