Sir Stuart Rose has become involved in a fresh clash with shareholders, this time over an investment in a karaoke company owned by fellow Marks and Spencer director Martha Lane Fox.

Leading shareholders are calling for the retailer to justify how the co-founder of Lastminute.com, who sits on both the retailer’s remuneration and audit committees as an independent non-executive director, can still be deemed independent under the Combined Code on corporate governance and stay in post.