MARKS & Spencer is this weekend facing a gathering storm over the controversial elevation of Sir Stuart Rose to the role of executive chairman.

Shareholders accounting for more than 20% of the retailer’s institutional base have voiced their opposition to the move, according to a poll carried out by The Sunday Times.

Dissenters include more than 10 of Britain’s most-powerful pension funds. The findings challenge M&S’s assertion that it has broad support for its reshuffle, which defies boardroom best-practice codes.

The discontent suggests M&S could be facing the biggest clash between a blue-chip company and its shareholders since Glaxo Smith Kline’s pay report was voted down in 2003 in protest at the size of boss Jean-Pierre Gar-nier’s rewards.

In another damaging attack, Schroders, one of M&S’s top 10 shareholders, is calling for the retailer to oust Rose unless he agrees to reverse the combination of the chairman and chief executive roles.

“Rose is sufficiently arrogant to say that if you don’t want me to take this role, I will leave,” said Richard Buxton, head of UK equities at Schroders, which has a 2% stake in the company.

“I would actually face up to that. The company is bigger than any individual.”

Lord Burns, the nonexecutive chairman of M&S, will this week carry out another round of meetings, designed to placate angry shareholders.

The row caught fire after Legal & General stepped up opposition to M&S’s bungled succession plan.

Peter Chambers, the chief executive of Legal & General Investment Management, told The Sunday Times: “We believe we have a moral responsibility to uphold corporate ethics in the UK and believe that the bellwether companies in the UK share this responsibility to uphold the highest standards of corporate governance.

“We don’t think they should be explaining why they are not complying – they should be complying.”

M&S was digging its heels in this weekend, insisting that it had nothing more to say. The retailer plans to write to all investors detailing why it believes Rose’s elevation to the executive chairmanship is in the best interests of the business.

In the meantime, Buxton claims M&S has refused to schedule a meeting with him. He also blamed Rose’s strategy for weak Christmas trading, above and beyond the harsh conditions on the high street.

Iain Richards, head of European governance at Morley Fund Management, said companies were stretching the spirit of the Combined Code for Corporate Governance for the sake of their own convenience.

“What you have got is an acceleration of precedents. If someone else is doing it, why can’t we?” he said. “Chief executives becoming chairmen is one example that is starting to become quite a concern for shareholders.”

It is understood discussions are still going on within M&S about whether Rose will be offered a pay rise to go with his more powerful position.

The retailer’s remuneration committee has still not met officially to propose any pay review, but Burns indicated earlier this month that he expected Rose’s base salary to be reviewed following the boardroom rejig. City sources told The Sunday Times that it was now 50-50 whether the pay deal would go ahead in the face of shareholder anger.

Around 25% of M&S is owned by retail investors, many of whom still regard Rose as their saviour.

Our research found that institutions holding 15% of the company – including L&G – were opposed to Rose combining the two top roles.

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