Marks & Spencer is understood to have given its second-biggest shareholder only one hour’s notice before announcing that it would be promoting Sir Stuart Rose to the position of executive chairman this summer, The Times has learnt.

Legal & General is believed to have been contacted at 9am on Monday to be told about the management shake-up where Sir Stuart, 58, will take control of the boardroom in June.

Hours after the announcement L&G issued a rare public statement condemning the shake-up as “unwelcome”, adding that it raised serious corporate governance issues.

The lack of consultation by Lord Burns, M&S’s outgoing chairman, is likely to raise more concern among the City’s institutional investors.

The decision to combine the role of chairman and chief executive to keep Sir Stuart Rose at M&S until 2011 provoked a furious response from some of the City’s most influential investment experts on Monday.

Peter Montagnon, head of investment affairs at the Association of British Insurers, said: “M&S has a lot of work to do to persuade people this is the right approach.”

It emerged yesterday that M&S contacted at least one large shareholder on Monday to see if it would put its name to a statement supporting the plan. The shareholder refused.

One investor said yesterday: “They say you have to comply with corporate governance guidelines or explain. It doesn’t seem they left themselves much time to do so.”

L&G yesterday refused to comment. M&S said it delayed informing key shareholders because of fears that details about the reshuffle could leak to the media.

A spokeswoman said: “It was a judgment call.” She added: “We have now spoken to half our institutional investor base to explain the reasons behind our announcement and they are all broadly supportive with one exception.”

However Pirc, the corporate governance watchdog, stepped up the pressure on the retailer in a scathing note to its clients.

Susanna Rust, Pirc research executive, said: “Sir Stuart Rose’s appointment flies in the face of a key governance principle enshrined in the Combined Code – the separation of powers at the head of the company.

“Perhaps luckily for M&S, Sir Stuart is not due to stand for reelection at this year’s annual general meeting, as he only stood for reelection in 2006.”

Sir Richard Greenbury, the former chief executive and chairman who led M&S to £1 billion of profits in 1997 and 1998, rushed to the retailer’s defence.

The retired executive, who was widely criticised for his autocratic style at M&S, told The Times: “If Sir Stuart and Lord Burns think this is the best move then I don’t see what the problem is.

“What is the difference between chief executive and executive chairman? It’s a different title, that’s all, he is still running the business.

“Stuart has done a good job and, put it this way, you wouldn’t want him to leave would you?”

Sir Richard spent ten years in charge at M&S and although guiding it to the position of second most profitable retailer in the world behind Wal-Mart, he was widely blamed for the group’s subsequent decline.

One leading institutional shareholder, who refused to be named, yesterday cited the fallout from Sir Richard’s reign as a reason why he was worried about the effects of Sir Stuart gaining too much power in the M&S boardroom.

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