Why is free admission to art galleries and museums sacrosanct, when free swimming is not? Free use of public swimming baths for pensioners and children was abolished by the Coalition as one of its first acts of fiscal rectitude. There was no organised lobby to defend this subsidy, which had previously been justified as in the interests of public health. Yet last week, when it was revealed that the banking heir Sir Denis Mahon had stipulated that the pieces in his £100m collection of Italian Baroque art could remain where they were in public galleries just so long as there were never any charges at those institutions, it seemed universally accepted that the great collector was speaking for all of us. Can it really be such an unchallengeable political principle that our leading metropolitan museums, sponsored by the Department for Culture, Media and Sport (DCMS), should not charge? Why is free swimming around the corner from children in Bolton or Plymouth self-evidently an extravagance, while free museums around the corner from the residents of Knightsbridge a sacred subsidy that cannot even be questioned? More precisely, what is so unique about fine art that it is thus sanctified by eternal subsidy? We don't offer, via the taxpayer, free seats at concerts of classical music or at the theatre; yet any arguments about the uplifting properties of Italian Baroque art could be equally applied to the music of Mozart or the plays of Shakespeare. John Carey some years ago took on this general proposition with his bracing book What Good Are The Arts? Carey observed there had never been a government more determined on public subsidy of high arts than the one led by a would-be painter called Adolf Hitler; his wider point was that appreciation of art does not in any way act as a check on the worst in human nature. The fact that the Third Reich believed in enormous subsidies for high culture is, obviously, no reflection on our own arts lobby. Nor is the fact that China is the only other significant nation to offer free museum entrance a proof there are Communist tendencies within our own dear Coalition. But what all of them have in common is the belief that it is worth subsidising the pursuits of the elite in order to persuade the masses to embrace the same pleasures. So although over 40 per cent of those who take advantage of this subsidy are foreign tourists (and in the case of the British Museum about 60 per cent), the ostensible political argument is that free access is the only way to bring in the most disadvantaged of the indigenous population. The figures, however, show that if this is indeed the purpose, it is a decreasingly well-directed policy. From representing over 9 per cent of the DCMS-sponsored galleries and museum audience in 2008-9, visits from adults in the lower socioeconomic groups fell to just 7.4 per cent of the total in 2011-2012. Yet over the same period, the overseas audience rose from 34.5 per cent to 42 per cent. Michael Dixon, the chairman of the National History Museum, argues that while the free admissions policy "costs approximately £45m a year to implement" an extra "£315m" is generated through additional revenues by tourists - presumably, in the Tate, by buying prints and suchlike in one of the gallery's seven shopping areas. Yet if free entry is such a business no-brainer, we might wonder why this cannot be sponsored by private corporate donors, who at the moment are used only to finance the "special" shows for which these DCMS-financed institutions actually do charge. This is the model of the Saatchi Gallery (declaration of interest - the proprietor is this columnist's brother-in-law). It has no entry charge and the cost of this policy is borne by firms seeking a pleasant association with art, not the taxpayer. But why should galleries paid by the taxpayer for such "generosity" bother to find the money themselves? This point will doubtless have occurred to the new Arts Council chief Sir Peter Bazalgette, who says that "subsidy sounds like a European wine lake." Dixon's claim came in direct response to a rare dissident voice, the Labour MP for Stoke-on-Trent Central, Tristram Hunt. His constituency contains the Potteries Museum and Art Gallery, which, while having "a ceramics collection second only to the V&A," has no state subsidy guaranteeing free admission. Hunt complained bitterly that this amounted to unfair competition: "This metropolitan club-class government has made sure that our global cultural icons are immune from the pressures hitting their regional colleagues." Oddly enough, I suspect the Conservatives feel that free gallery entrance - even concentrated on salubrious Kensington and Bloomsbury - is a way of demonstrating that it is not a party of toffs looking after its own interests. This is one explanation of its panic six years ago when its then shadow secretary of state for culture, Hugo Swire, argued in a newspaper interview that the DCMS-sponsored museums and galleries should be allowed to charge, if they wished: "They could use the money to make their facilities even better and could have special arrangements allowing continued free access for children [and] students." Swire was immediately forced by Tory high command to recant this unobjectionable suggestion and fired from the job soon after. The immensely well-connected and media-savvy arts mafia must have been quietly satisfied. The subsidy of universal free access (not just for children or students) to our grandest metropolitan galleries might also be seen as an example of long-standing Whitehall bias. Fans of the original Yes Minister might recall the episode entitled "The Middle-Class Rip-Off," in which Sir Humphrey Appleby attempted to educate his young colleague Bernard, when the more junior civil servant questioned the extent of the state's subsidy of fine art. Sir Humphrey (calmly): Bernard, subsidy is for art, for culture. (Almost furiously) It is not to be given to what the people want! It is for what the people don't want but ought to have! In fact, Sir Humphrey really did enjoy nothing more than an evening at the Opera House: he was a genuine (if fictional) highbrow. I suspect the current occupants of the Media and Culture ministry, politicians or otherwise, would not know one end of Guercino's "The Presentation of Jesus in the Temple" from the other. They only know it sounds good to say it's "free" - as if none of us will be paying for its upkeep in perpetuity.