Sir Stuart Rose has hit back at rebel Marks & Spencer shareholders in the spiralling corporate governance row that is threatening to engulf the high street retailer.

The Association of British Insurers (ABI) raised fresh concerns over the chief executive’s dominance in the boardroom this week, after it emerged that Sir Stuart had invested in a new business venture set up by Martha Lane-Fox, a nonexecutive M&S director. The ABI said that the move meant that Ms Lane-Fox could no longer be considered an independent voice in the boardroom.

However, speaking at the opening of what the retailer has called its first eco-factory yesterday, Sir Stuart indicated that his patience was running out.

“I’ve noted the ABI’s comments,” he said, “but this week I have been concentrating on running our business, visiting our suppliers in Sri Lanka and India and confirming our joint venture with Reliance [M&S’s new Indian partner].”

This week M&S insisted that the investment in Ms Lane-Fox’s venture - a chain of karaoke bars – was a private matter.

The retailer has been trying to placate investors since announcing in March that Sir Stuart would be taking on a combined role of chief executive and chairman in June. The move flies in the face of corporate governance best practice, which stipulates that the roles should be separate to ensure a balance of views in the boardroom.

M&S has invested £200,000 in its eco-factory, which will be carbon neutral and produce “green” lingerie for the retailer’s Autograph and Per Una ranges. The factory will use 40 per cent less energy and 50 per cent less water than typical facilities. It houses Sri Lanka’s largest solar panel installation.

Sir Stuart said: “It’s not just a pretty building. It’s a project that establishes what we believe to be the first eco-factory in the world.”

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