When Eastwood Tory MP Allan Stewart resigned amid allegations of adultery last week, Scottish Conservatives were looking to their leader to stand in his place.
Sir Michael, 51, is a Kirk elder and the father of three teenage children. He is also a Tory paternalist who sat on the board of trustees of the British Diabetic Association and was a director of the Children's Hospice Association, Scotland.
Crucially, in the current political climate, he seemed adept in the art of sleaze control and apparently unflappable in the face of potential political embarrassment.
When Ian Greer, the political lobbyist, revealed last October that Sir Michael had been among 21 Tories to have received cash from his company, the Scottish Tory chairman reacted with style.
He brazenly summoned the press to his home and told them the pounds 500 donation was a pre-election gift for the party from a known Tory. "If this is sleaze, then I'm a banana," he said.
Sir Michael has been less charitable in his comments concerning the financial arrangements of rival politicians.
He provoked outrage last year by compiling a "Scotland's Dirty Dozen" dossier of SNP and Labour councils who he accused of being "bandits" guilty of profligate spending.
His own business acumen is not in question. A qualified accountant, he is the founder of his own business consultancy, Michael Hirst Associates.
He demonstrated his entrepreneurial spirit before the 1995 British Open golf tournament when he rented his house, close to St Andrews, to the BBC. He said later that the house was a "private business interest" of his wife Naomi, who used to work for the BBC.
Sir Michael, a lifelong stalwart of Scottish Conservatism, was educated at the Glasgow Academy and the University of Glasgow, where he was president of the Conservative Club. He was MP for Glasgow Strathkelvin and Bearsden in 1983-87, but lost the seat to Sam Galbraith, the Labour neurosurgeon.
In parliament, he sat on the commons select committee on Scottish Affairs and he was knighted in 1992 for "political and public service".
While not as zealous as some in campaigning for family values, he has not been slow to criticise others for moral indiscretions.
Earlier this year, he admonished the Scottish author Iain Banks for publicly stating that the drug ecstasy was safe. Sir Michael said Banks had been "recklessly irresponsible" and that people in the public eye had a duty to act as role models for youngsters.
Yet, amid the right-wing backlash over the revelation last year that two gay men in Edinburgh had adopted a baby girl born to a surrogate mother in America, Sir Michael chose not to criticise. "From a personal point of view," he said, "if the child is being brought up in a stable, loving home, then it is fine."Reuse content