Euan's snog wasn't in the PR plan

You have to admire his cheek. On Tuesday the Prime Minister made a formal protest to the Press Complaints Commission after the Daily Sport published pictures of his 15-year-old son kissing another teenager in a nightclub. Mr Blair and his wife Cherie believe the photographs breached two clauses of the editors' code of practice, including one restricting the use of material on the child of a famous parent. Excuse me? Is this the same couple who, only a month ago, shared with us not just the news of Mrs Blair's latest pregnancy but Mr Blair's reaction to impending fatherhood and hints about where the unexpected conception might have taken place?

Cabinet colleagues outdid each other in sycophancy as they congratulated the happy couple, while female columnists twittered about how the Blairs would cope with the new arrival. There was even some public back-slapping about the Prime Minister's display of virility - favourably compared, I seem to remember, with Bill Clinton's sole foray into fatherhood - and not a single complaint from No 10 about anyone's privacy being invaded. Not long after the official announcement, Mrs Blair was photographed at Downing Street, posing serenely with her hands clasped over a just-discernible bump.

It is, I suppose, one way of solving the working-wife problem, which Mr Clinton also had to deal with during his first administration. In less than three years, Mrs Blair has been transformed from a formidable lawyer into a Madonna-like figure who, as her husband's poll ratings inevitably begin to slip, is unlikely to worry even the most traditional voter. Baby Blair, a nameless foetus which has yet to emerge into the world, has already been subjected to a barrage of publicity, apparently with the cheerful acquiescence of his or her parents. Naturally the couple protested - or spin doctors let it be known on their behalf - that they regretted the speed with which the news had spread, obliging them to answer a direct question from a tabloid newspaper.

But does anyone seriously believe there was a discussion in the Blair household about how to handle the announcement with the least fuss? "The Prime Minister's spokesman confirmed last night that Mrs Blair is pregnant. There will be no further comment on this entirely private event" - very New Labour, I don't think. The media are often held to be at fault here, as though celebrities - which the present Prime Minister and his wife, unlike even the Thatchers, undoubtedly are - have no choice but to co- operate with the press. What this overlooks is the extent to which people such as the Blairs exploit the tabloid obsession with private life, as long as the results are to their advantage.

This is an administration which thinks the trivial information that Mr Blair has started wearing reading glasses is of such significance that it has to be spun into a "world exclusive", revealed to a carefully selected audience - the readers of Woman's Own - along with a boyishly self-deprecating quote from the Prime Minister. No government in British history has been so obsessed with appearances, and Mr Blair's role as the father of a growing family is an essential element of his image. The children do not appear on this year's No 10 Christmas card, whose regal ghastliness recalls early offerings from the Prince and Princess of Wales, but in previous years there has been no hesitation about pictur- ing the Blairs en famille.

Personally, I could not care less how many children the Prime Minister has or what they do in their spare time. But you do not have to be Mystic Meg to predict that, when Mrs Blair gives birth in May, we will be treated to a blow-by-blow account and photographs of the Prime Minister, emerging exhausted but grinning from the labour ward. At what point, then, does Baby Blair cease to be public property? Perhaps when the christening is over, and the story has been milked for all it is worth. When his or her parents make an arbitrary decision, as they did last week, that their children are none of our business.

Most of us would be happy to accept the latter proposition, but only if the Blairs act upon it with at least a semblance of consistency. They have performed the singular feat of making me feel sorry for the editor of the Daily Sport. Instead of being censured, as he almost certainly will be, he should be congratulated for exposing the double standards that Downing Street is operating. It is all a far cry from the old days, when prime ministers got on with running the country and kept their families in the background. Most of the population would not have been able to name Harold Wilson's children, let alone recognise one of them snogging in a nightclub.