Peter's healthy sense of self-preservation

A benign variant of that trouble thankfully, but unmistakeably a condition which affects men who have passed their half century.

Lord Mandelson can't be accused of failing to look after himself - though approaching 56 he is trimmer than ever, saying he achieves this by being "a bit hungry all the time".

Travelling recently with the man who is effectively deputy prime minister, I can vouch for that. Like a lot of health-conscious people, he talks about the food he isn't eating: praising an adviser for being "in charge of cake" on journeys (though none was consumed on ours) and detailing a lavish barbecue at a civil servant's house as a culinary high point.

He sings the praises of green tea as only a health convert would: not least its cancer-preventing qualities, with comic reference to a study in rats.

Lord Mandelson has his own Peter Pan qualities. He has escaped seemingly fatal political situations with such regularity he is regarded with some fondness as a survivor by the people who found him most trying in his earlier incarnations. He insists that a former party lifestyle is in the past: "I do early dinner then I'm in bed by 10 on a Saturday night."

In the hedonist setting of Nat Rothschild's Corfu hideaway he dined with the group (having long exchanged a socialist social life for a socialite one) and took walks by the sea, but spent a lot of time hidden away with his paperwork.

At weekends he puffs his way up Primrose Hill with two dogs and cycles through Regent's Park, at what one witness describes as an "alarming rate".

Like his old master Mr Blair, there is a strong attention to physical condition, accompanied by the tinge of anxiety at the creeping years and a shimmer of self-awareness.

The Mandelsonian haircut and glossy condition are unchanging factors. On his return to British politics he suffered an attack of kidney stones, another of those wild-card afflictions which can strike even the best-maintained in middle age. That and the demands of his multi-department job and role as close comforter and adviser to the workaholic Gordon Brown led to a new asceticism.

Lord Mandelson believes British politicians should pay more attention to personal grooming, so invests in fine grey suits and impeccable white shirts, and has acquired a taste for well-shined loafers: a continental touch acquired in Brussels. Vanity? A bit.

But he has an acute sense of self-preservation, both personal and political: it's what being Peter is all about.