Is there room at the top for good relationships?

They have one at Marks & Spencer, they used to have one at Marconi and Asda, you'd hope they have one at BSkyB, but by all accounts they don't have one at BAE Systems.

They have one at Marks & Spencer, they used to have one at Marconi and Asda, you'd hope they have one at BSkyB, but by all accounts they don't have one at BAE Systems.

The relationship between a company's chief executive and chairman - be it, in the case of M&S, Marconi, Asda and BSkyB, a notably close one, or much cooler as at BAE Systems - has been thrown into the spotlight in recent weeks because of a row engulfing M&S's boardroom.

Non-executive director Paul Myners became chairman last August, but temporarily: he was due to step down at July's annual general meeting. But it is understood he now wants to stay, a move reportedly endorsed by chief executive Stuart Rose.

That is a problem for M&S's non-executive directors, led by Kevin Lomax. He is understood to be concerned about the cosy relationship that has developed between the two men since they fended off Philip Green's £9bn hostile approach last summer. While the Higgs review of corporate governance accepted that chairmen can never be truly independent, they are supposed to form a "bridge" between the executives who run the company and the non-executives, who ensure it is being run as well as it can be. And that requires an element of distance.

Geoff Lindy, strategic adviser on corporate governance at the powerful National Association of Pension Funds, says: "Each individual board has to determine the relationship. If you are in a turnaround situation or a contested bid is on the horizon, then inevitably it must bring the chairman and chief executive closer together. It forces them together, there's no doubt about that.

"But the strategy, having been developed by the board, is executed by the executives, so there has to be some distance between the chairman and chief executive."

One institutional investor adds: "If they are close, chairmen identify too closely with the strategy. It potentially stops the chief executive from taking as robust action as is needed."

That is not to say a close relationship is doomed. At BSkyB, chief executive James Murdoch is the son of chairman Rupert. His appointment caused uproar but a string of solid results has since quietened opponents.

Allan Leighton and Archie Norman, Asda's chief executive and chairman respectively between 1996 and 1999, worked closely to produce one of retail's greatest turnarounds.

Yet for every success story, there is a cautionary tale. Perhaps the most famous is provided by Marconi. During the tech boom, Lord Simpson, chief executive, and finance director John Mayo spent the prudent Lord Weinstock's £1.4bn cash pile, transforming the old GEC under the gaze of chairman Sir Roger Hurn.

Marconi, though, struggled when the bubble burst and eventually had to warn investors. It scheduled a board meeting to get approval for the move on 4 July 2001. But there was a problem: the previous night it had agreed to sell a business, which it had to announce. Yet if it had, just hours before issuing a profits warning, it would have created a false market and broken City rules.

Instead of bringing the meeting forward, so that both announcements could be made together, Marconi suspended trading. It got approval as planned but the move panicked the City, and investors sold in droves when trading resumed.

An official probe into events that day criticised both Lord Simpson and Sir Roger. Mr Mayo has claimed he lobbied his chairman and chief executive to bring the board meeting forward, but both refused. All three have left the company.

No one is suggesting such a fate would befall M&S, and a relationship that is not close enough can be just as damaging. For example, since being made BAE chairman nine months ago, Dick Olver has clashed with chief executive Mike Turner and upset colleagues by getting involved in areas traditionally reserved for executive directors.

But times are tough on the high street and Mr Rose has much to do to turn the retailer round. Should he falter, shareholders will look for a scapegoat - or two: "It's only when things unravel that we look for causes and blame," notes one.

M&S wants the issue settled, ideally by the final results on 24 May, if not before. Mr Lomax has a short-list of candidates for the chairmanship but there has been criticism that, nine months down the line, a list is all he has.

There is further pressure in that investors, such as Brandes, M&S's biggest with some 15 per cent, back Mr Myners. This could prove crucial. As Mr Lindy says: "These are not rules, it's a code. The shareholders make up their own minds. That's the beauty of the UK situation."

There are not always definitive rights or wrongs in relationships at the top. Sometimes, fights are vital for the greater good of the company; at others, a united team is the only way to fend off predators or turn a company around. Instead, as with all things to do with corporate governance, it is a delicate question of balance.