Trending: More leisure, Prime Minister?

David Cameron complaining about a work/life clash is enough to make our eyes glaze over, says John Walsh. What he should work on is his jolly/serious axis

Work, rest and play: David Cameron (Reuters)

Poor David Cameron. He just can't get it right, can he? Yesterday, he told Radio 4's Today programme that he could regularly be found in his kitchen at 5.45am, working on his red boxes, but it wasn't enough for John Humphrys. The Welsh Torquemada upbraided the PM for being too relaxed about the awful gravity of his calling.

"We read a lot about you, with yer computer games, yer box-sets of DVDs and yer date nights," sneered Humphrys (who seemed to think the phrase was "day nights") before asking, "You're not a bit lazy are you? Just a little bit?"

He cited an unnamed Tory backbencher who'd told the papers that Cameron is "putting the school run ahead of the national interest". Cameron admitted he drove his children to school once a month or (oh no!) sometimes more, but suggested: "It's got to be possible to be a good husband, a good father and a good Prime Minister as well... If you're completely fried and exhausted and never have time for a jog or a game of tennis, you'll make bad judgements because you're exhausted and stressed and all the rest of it."

We all agree with that, don't we? Getting the "work/life balance" right is a universal need. It was given a big government push in 2000 by Tony Blair and David Blunkett, after research revealed that "long and inflexible working hours contribute to poor health, family life and productivity". It affects every one of Britain's 60 million people except a small demographic – prime ministers. They cannot be seen to work too hard or relax too much. If they're known for the former, they're Gordon Brown-style, single-minded, humourless, Stalinist workaholics. If for the latter, they're dilettante, sleepy-headed, time-serving dolts like Ronald Reagan and George W Bush.

It's not about what they actually do or don't do, of course, but how they're perceived by media and newspapers. So they have to strive for a new equilibrium: the earnest/benevolent balance.

Mrs Thatcher was something of a genius for getting this balance right. She was thought cold and imperious by enemies, strong and implacable by fans, a stateswoman to her stockinged feet. But she also liked to play the pinny-wearing housewife, the espouser of family values, devoted to her husband. Few in the political arena were fooled ("Mata Hari," said the journalist Mary Riddell, "was modulated into Mrs Homepride") but voters bought it, again and again.

John Major radiated neither political conviction nor rumpus-room jollity at any discernible level. Tony Blair balanced furrowed-brow earnestness with guitar-toting, rock-stars-at-Number-10 frivolity for six years until 2003, when his seriousness was shown to be dissimulation. Gordon Brown's every attempt at levity and down-home fun crashed in flames like North Korean missiles.

And so Mr Cameron wrestles with hitherto unasked questions: which box-sets of DVDs are acceptable for a PM to watch? Does one dinner with Samantha at Hereford Road (a west London favourite) balance six evenings at No 11 discussing fiscal strategy with George Osborne? Does reading a book when you're not on holiday count as good or bad? God, the importance of being earnest – but the importance of seeming human too.