A major Marks & Spencer shareholder has called on the retailer to appoint an independent chairman within 15 months.

The Local Authority Pension Fund Forum (LAPFF) has filed a shareholder resolution, asking for an appointment by July 2010.

LAPFF executive chairman Ian Greenwood said the resolution was intended to provide a “safety valve” for shareholders who wanted the company to uphold best practice but did not want to oust existing chairman and chief executive Sir Stuart Rose.

Greenwood told The Telegraph: “Since this case represents such a significant breach of long-established and widely-accepted best practice it is incumbent on shareholders to challenge it.”

An M&S spokesperson said the retailer was “disappointed” at the resolution.

Sir Richard Greenbury, who was chairman and chief executive of the retailer between 1988 and 1998, is backing Rose, according to The Times.

Greenbury said: “They should leave him alone. I think he’s done a terrific job.”

Two contenders for the role of chairman include Allan Leighton and Archie Norman, the duo that led the turnaround of Asda in the early 1990s. According to The Observer, the two have told friends they would be interested in the role.