IT’s a funny old world. The man who, as head of Marks & Spencer’s pension-fund trustees, helped to scupper Philip Green’s bid for the retailer last summer, has a new job. He has become the government’s first pensions-regulation supremo.

And David Norgrove, who was actually ousted from his executive slot at M&S before the whole Green saga, is not slow to see the amusing side of all this. A few have already asked, what qualifications does he have to take on this new supremo role? A decade at the Treasury, three years as private secretary to Margaret Thatcher, 16 years as an executive at M&S, culminating in a conspicuously unsuccessful stint as head of clothing. Does he owe the job to all that controversy over the blocking of Green’s bid? “Well, it didn’t come up in interview, but it was one of the things that encouraged me to apply for the job,” he smiles.

More likely, his adaptability helped. Tall, bald, poshly spoken, rather like an elongated Ian Duncan Smith, Norgrove has a capacity for reinventing himself. He has been an economist, a banker (loaned out to Chicago First National by the Treasury), an adviser, a strategist, a retailer, even a shepherd — and now chairman of the new Pensions Regulator.

Next month he takes on the raft of new powers given to the pension supremo by the 2004 Pensions Act, plus 350 staff to help him exercise them. He now has the capacity to have a considerable impact on British business.

He can hunt down misbehaving companies that aren’t filling their occupational pension funds properly. He can interfere with takeover bids where the position of the pension fund could be jeopardised (as might have been the case with the Green bid).

“It’s not a recipe for popularity,” says Norgrove drolly. But at 57, absolved from money worries — he left M&S with a good payoff and a sizable pension — he wanted the focus of a challenging task.

He is, however, a controversial choice, not least because of his role in undermining Green’s £9.1 billion bid for M&S last summer. Back then, as head of M&S’s pension-fund trustees, he let it be known that Green might be expected to find yet more money to top up the fund if the highly leveraged bid succeeded.

Why? Because the credit-worthiness of the company could come into doubt, and the trustees would then have to change the fund’s investment strategy, requiring bigger contributions from the firm. It looked to some like a very effective poison pill.

More tellingly, Norgrove refused to meet Green, which made the BHS owner apoplectic. “I have no qualms about that now,” says Norgrove, smiling at the thought. “The company was refusing to allow him to do due diligence, so why should we meet him?” Has he met him since? “Just once,” he laughs, “at a reception last autumn. He is one of a number of people who have jabbed me in the chest in my career.”

Who was the last one? “Rick Greenbury, my former boss at M&S.”

Wasn’t he a Greenbury man? “Is anyone a Greenbury man?” replies Norgrove, arching his eyebrows mischievously.

There is a slightly patrician edge to Norgrove’s wit, which is all the more intriguing when you consider his background. Brought up in Peckham, south London, the eldest son of a school janitor, he describes his roots as working class, at least until he was swept off to Christ’s Hospital boarding school in Sussex on a poor boys’ scholarship.

Now he lives in Islington, north London, with holiday homes in Berkshire and Scotland (his wife grew up in Glasgow), and cites working outdoors — leisure, not paid — as his favourite activity. Very bright, softly charming and extremely well-connected in Whitehall, Norgrove is as much a self-made man as Green and Greenbury ever were, just in smoother guise.