When Louise Patten, as chairman of Brixton, brutally sacked Tim Wheeler, her chief executive, on Tuesday, few remembered that it was, in fact, the second time that she had wielded the stiletto in the boardroom.

In 2000 David Simons, chief executive of the Somerfield supermarket chain, was also dismissed, after an early morning meeting with Lady Patten of Wincanton, as she had become three years before when her husband, John Patten, the Tory politician, was made a life peer.

Somerfield, a retail basket case that had issued a string of profit warnings after Mr Simons bought the Kwik Save chain in 1998, had been forced to pull out of buyout talks. Lady Patten had been caretaker chairman after her predecessor, Andrew Thomas, took retirement.

Known as the “queen of the non-executives”, the former banker-turned-management consultant has filled a series of boardroom slots. Her first was the Hilton Group; Harveys Furnishings and Great Universal Stores followed.

But her two most high-profile jobs brought controversy with them. She was in charge of the remuneration committee at Marks & Spencer that approved a bonus scheme for senior management seen by some as overgenerous. She was also a non-executive of the tottering mortgage bank Bradford & Bingley and was asked to stay on after its nationalisation. As one observer said: “She does seem to be in the wrong place at the wrong time.”

Educated at St Paul's Girls' School, she married in 1978. When her husband became Education Secretary in 1992, she was seen as one of a new breed of Tory wives not prepared merely to simper decoratively next to their husbands at party conference.

Instead, she and others, such as Caroline Waldegrave and Fiona Fowler, were seen as go-getting career women. At the time Lady Patten was a management consultant at PA Consulting, where her income was reckoned to be triple that of her husband. He conceded that of the two, she had the more high-pressure job.

After Oxford she worked at Citibank and Wells Fargo before the move into consulting in 1985. In 1993 she joined Bain & Co, where she remains a senior adviser.

One senior executive who has served at board level with her said: “She's intelligent, interesting and charming. She's not rude — women are very rarely rude — but she's certainly direct. She'll call a spade a spade, but in a very charming way.”

Someone else who has worked with her says: “She's clever, direct and quite glamorous. When she has something to say, it's going to be hard to ignore.”

She is little-known outside the City and prefers to operate without publicity. This proved impossible at M&S, which she joined in 2006. The board came in for criticism after Sir Stuart Rose was allowed to add chairman to his role as chief executive, in apparent breach of corporate governance guidelines. Last summer there was a further revolt. Lady Patten and her committee had rubber-stamped the decision to cut the target that Sir Stuart had to reach to earn a £4.5 million bonus under the company's long-term incentive scheme. The retailer insisted that this reflected the slowdown on the high street, which was making it difficult to achieve the levels of growth that it had seen in recent years.

The M&S publicity machine also insisted that the new arrangements had the full support of shareholders. It became embarrassingly apparent that this was untrue, and a subsequent profit warning did not help. One shareholder watchdog called on investors to vote against Sir Stuart's re-election.

Even as the row at Marks came to a head, Lady Patten was firefighting elsewhere. As a non-executive at Bradford & Bingley, she was already being criticised for her role in the bank's near-collapse, and there were further complaints that a failed bid to sell 23 per cent of the bank to a private equity group was being railroaded through without giving shareholders a proper voice.

When she became chairman of Brixton in 2003, she said of the industrial property specialist: “I really like the people, if that doesn't sound too wet.” Six years on, much of this amity has evaporated, the shares have tumbled and the board is accused of being too slow to shore up the defences in the face of the recession. Mr Wheeler was the obvious fall guy.

The ousted chief executive is well-known for quoting Bob Dylan in an earlier financial statement: “There must be some way out of here ...”

As a fan, Mr Wheeler will be familiar with another hallowed Dylan lyric: “You don't need a weatherman to know which way the wind blows.”

Rough with the smooth

Background - St Paul's Girls' School; St Hugh's College, Oxford; investment banking, management consulting

Big break - Joining PA Consulting in 1985

Worst break - Simultaneous entanglement in boardroom rows at Marks & Spencer and Bradford & Bingley

Style - Understated to the point of invisibility