This weekend Lord Turner must be trying to recall the exact moment in his life when the butterfly of fate flapped its wings and wafted him inexorably towards a job where he would become a political punchbag for daring to change the terms of public debate on pensions.

One such moment stands out in the early 1980s when Adair Turner was working for McKinsey, the management consultants, with a group of high-flyers that included William Hague, Archie Norman, Howard Davies and Norman Blackwell.

The team was supposed to be advising Citicorp, the American bank, on strategy, but Turner admits he didn’t have much of a clue and Hague, a beginner, even less.

“For the better part of three weeks, William Hague bashed these figures into a computer,” Turner recalled. “We then processed them and tried to understand something about profitability and banking. At the end of it we found out that all the figures we’d been given were completely and utterly wrong. I said to William, ‘Sorry, you’d better start all over again’. He’s been blaming me for that event ever since.”

Hague went on to become the Tories’ sometime leader, adopting an anti-euro stance that Turner claims jokingly was a cussed response to his own advocacy of the European currency.

Norman became chairman of Asda, the retailer, and also the Tory party vice-chairman. Blackwell became John Major’s head of policy. Davies became director-general of the CBI and is now director of the London School of Economics. They are still friends, naturally.

This group of young bloods represented a new breed of fiercely meritocratic pragmatists who were increasingly to dominate British public life. Unusually they were as fascinated by politics and public policy as they were by business.

Interestingly, those in the group who entered politics have been tainted by failure and Turner’s anecdote is a gift to critics who claim that McKinsey man delivers less than he promises.

Turner stayed with the company for 13 years to become the consummate McKinsey technocrat. So it comes as no surprise that his massive Pensions Commission report bears the McKinsey stamp of rigorous analysis, even though its 460 pages were scorched by a pre-emptive strike from Gordon Brown, the chancellor, who implied in a leaked letter that its key proposals were unaffordable and unsustainable.

Nevertheless, the fruit of Turner’s three-year labours has been generally well received. It proposes a more generous state pension linked to earnings rather than prices, with less means testing (ideas that so displeased the chancellor) and a new state pension age for men and women that would rise to 66 by 2030 and 67 by 2040 and 68 at 2050. He also suggested a national pension savings scheme for those without occupational or private pensions, into which workers would pay 4% of salary, employers 3% and the government 1%. Those who wished could opt out.

At 50, Turner is a millionaire who is now surely owed more time with his antique collection at the grand mansion in Kensington, west London, that he shares with his Irish wife Orna Ni Chionna, who was a member of his McKinsey team. They have two daughters, Eleanor, 17, and Julia, 14.

However, this polished and ever-so slightly smug man, squeezed between No 10 and No 11, was soon obliged to come out fighting. In his presentation he had indirectly accused Brown of indulging in “fairy-tale economics”, but by Friday the gloves were off and he attacked the chancellor’s criticism as “a caricature” that was “not a contribution to a sane argument”.

Turner has started the great pensions debate, but the question is whether he will campaign for his blueprint for reform? Once embraced by Tony Blair — and Brown — as an honest broker with little political baggage, he now finds his appetite for public reform waning after carrying out a review of National Health Service management and steering the low pay commission.