By the end of childhood, a British child is far more likely to have a television in his bedroom than a father living at home. In large areas of the country fatherhood, other than in the rawest, most biological and inseminatory sense, is virtually unknown. I remember a young patient who replied to me, when asked what her father did for a living: "Do you mean my father at the moment?" This is infinitely sad as well as socially disastrous.

A lot of what David Cameron said to mark Fathers' Day was right, therefore; and yet, at the same time, it was deeply repellent. First there was the language he used, a mixture of undignified and condescending demotic and mid-Atlantic psychobabble. Just as Mr Blair was never Anthony, so for Mr Cameron dads are there for you (the kids), so that there comes a time when you (the kids) turn to them (the dads) and a light bulb suddenly flicks on inside your head. Psychobabble, the language of Rousseau's Confessions without the confessions, does not come much shallower than this.

This choice of language was a transparent attempt by Mr Cameron to persuade the public that he is just a normal chap – or as he would no doubt put it, guy – who happens to have found his way into 10 Downing Street, in more or less the same way I sometimes go down to the Castle Tea Rooms for my lunch.

But worse still is the sentimentality of what he had to say, closely allied as it was, to its utter complacency and ruthlessness, both express and implied. Mr Cameron told us that he would not be who or where he is today had it not been for his father. He assumed, of course, that this was a recommendation of his father's fatherhood. Whether history takes the same view remains to be seen; it might, but it might not.

I have no reason to suppose that Mr Cameron did not genuinely love and revere his father, but the political use he has now chosen to make of that love and reverence causes me to shudder in the way I shudder when a singer misses a note. There is something wrong, kitsch or ersatz about it. The photograph of Mr Cameron embracing his father while the people around them applauded has the same effect; the gesture's sincerity is called into question by the public circumstances in which it was made. An office-seeker who is prepared to parade his sentiments in public is ruthless, not sensitive.

Sentimentality is frequently the reverse side of the coin of cruelty, and this was shown by Mr Cameron's call in the same article for the stigmatisation of absent fathers. It is one thing for stigma to arise spontaneously from a society's shared mores, when such stigmatisation may be for good or evil, or some mixture of both. But it is quite another when the head of a government calls for it.

Are we to have a National Stigmatisation Agency, complete with public denunciation ceremonies, to which admission could be charged? This might help to reduce our deficit, but it would be very nasty.

In resorting to the sentimental use of his own happy relations with his father, Mr Cameron was implicitly expressing contempt for the people of his own country, whom he thereby deemed incapable of grasping an argument about the desirability of fatherhood for children without the aid of Hello! magazine-type illustrations. This is to reduce our politics to the intellectual level of American tele-evangelism.

After having asked us to hug a hoodie, Mr Cameron now asks us to celebrate and embrace our responsibilities. It is surely time for Mr Cameron to get in touch with his language, and ring-fence his metaphors.

Dr Theodore Dalrymple is the author of "Spoilt Rotten: The Toxic Cult of Sentimentality" (Gibson Press)