Is it time for that Cabinet minister (nudge, nudge: you know the one) to grass on himself?

So who is the cabinet minister whose son has been accused of drug- dealing? The question was raised at a dinner party in London the other night - indeed, it must have been raised at a thousand such occasions all over the country in the past few days. Half of those present on this particular occasion knew the identity of the minister, because they had direct access to people who knew. One person had come across it on the Internet. Others had worked it out from the way the stories had been written in the papers. By the time the evening was over, of course, everyone was in on the secret. And with the subsequent parties of the week the tawdry fact will ripple through what we now call the chattering classes.

Once they were called the metropolitan elite, and there was a time when all manner of political titbits circulated among them; gossip denied to the general public. Sometimes it was just tittle-tattle. At other times whispers of turpitude led to mysterious resignations in high places. At its high point it concerned itself with clandestine scandal around the royal household, which eventually led to the abdication of King Edward VIII.

Democracy and an unfettered press have, by and large, put an end to the notion that "everyone who counts, knows". Today it is generally affirmed that there is above all one group which counts and which also needs to know: the electorate. But does it need to know about the adolescent misdemeanours of politician's children?

Some have said that the cabinet minister concerned acted cynically in frog-marching the unfortunate youth down to the local police station after the politician received a call from the Mirror to report that one of its 30-year-old journalists had bought pounds 10 worth of cannabis from the 17-year- old boy. The politician, they said, had shopped his or her own son to protect their political career.

That reaction is unfair. Most responsible parents would have done the same thing on the grounds that immediately confronting the problem would minimise the damage. In the unlikely event that the police did prosecute, the teenager's swift contrition would undoubtedly lead most magistrates towards leniency.

The dilemma which confronts the minister is a different one. It may be the right thing for a father to persuade his son to confess to the police, but should a politician not also own up to the public? As a parent he knows this is a bad idea: identifying himself would be tantamount to doing what he hopes his prompt action has averted - once the epithet "Minister X's drug-dealer son" gets into the newspaper cuttings it will for ever dog the unhappy young man and make him a prisoner of his past. Though most of those in his circle of acquaintances and schoolmates will already know by now - and probably will not disapprove - of him reportedly selling pounds 10 worth of dope in a pub, the 17-year-old's parents may fear that future employers could take a different view.

But what is best for a parent is not necessarily what is best for a politician. If that minister speaks now, or in the future, on home affairs, education, health, social security or any one of the portfolios where "parental responsibility" can become an issue, it is hard to see how his or her credibility might not be called into question. This government has made so great a point of the issue - whether in the area of curfews for unruly children or single parents' responsibility to work - that it has already laid itself open to general accusations of a new puritanism. Even if malicious Tory backbenchers do not spice their question with asides to the effect that "I blame the parents myself", the minister can be sure that the press will be watching like hawks, or vultures, for any trace of inconsistency, any suspicion that policy is being reinforced or diluted, or any sign that this hapless parent is having to pass certain aspects of business to colleagues leaving him or her a lame duck minister in those areas. In the event of anything like that the press might reveal the full sorry facts.

Lord Wakeham has been huffing and puffing that the new tighter Press Complaints Commission code of practice forbids such revelation. True, it does say under Clause 6: "where material about the private life of a child is published, there must be justification for publication other than the fame, notoriety or position of his or her parents or guardian". But the code also allows exemptions where publication can be demonstrated to be in the public interest. Clause 1(iii) of this covers material "preventing the public from being misled by some statement or action". Newspaper lawyers have already suggested that shifts in the nuance of political pronouncements on the question of parental responsibility might well constitute a defence in the present case.

Certainly the position has not been helped by the arrest of the Mirror journalist who set out to expose the minister's teenage son. There were those who expressed glee at the arrest of a reporter engaged in what they regard as meretricious journalism with its sanctimonious pronouncements over such an absurd commonplace little crime. But it is an unhelpful development. For a start, there will be those for whom it smacks of "who will rid me of this turbulent press?" But more importantly it drags into the case the whole question of the freedom of the press. It was politically maladroit because it has seriously upped the ante.

The dilemma between parent and politician is not a new one. It was the one faced by Harriet Harman over her son's education, and which she resolved by declaring that her responsibility as a parent must always come first. It may well be that the un-named cabinet minister with the rebellious son has made the same decision. For all we know his resignation - or a request to be moved to a different portfolio - may be preoccupying the Prime Minister in his Seychelles holiday hideaway and a reshuffle will be forced. Or perhaps he is just sitting tight, and hoping it will all go away.