GREETINGS, fellow forelock-tugging, serf-like 'subjects' of a gracious, noble, victorious, happy and glorious Sovereign. Prithee, answer this question: are you happy living in Disneyland instead of a true democracy? Can we really go on in this modern era with a fairytale for a constitution – and a granny Queen or her son, the Prince of Fogeys, long to reign o'er us?

Anti-monarchists plan a legal challenge to the oath of loyalty which MPs, judges, people seeking citizenship, peers, archbishops, bishops and police constables swear to the Queen. The campaign group Republic will seek a judicial review through a test case if one MP or an official refuses to take the oath. A couple of dozen MPs from all three main parties have dared to call for the scrapping of their 500-year-old oath of loyalty to the so-called 'Ruler' of the United Kingdom, asking instead to swear allegiance to their constituents and the nation. This dangerously democratic move has brought the usual creaking knee-jerk response from the mealy-mouthed monarchists in Parliament who describe it as "constitutional vandalism", a personal insult to the Queen and an attempt to republicanise our constitution (which doesn't exist – at least, not on paper).

Now we have His Royal Highness (how high above us vassals? Not very, methinks) Prince Charles, ranting in that remarkably refined drawl about GM crops. As the living result of generations of breeding from a carefully controlled gene pool, he may have first-person experience of genetic juggling – but why should we pay more attention to Charles than to any other well-meaning, concerned crank?

His position as Him-in-waiting-for-his-Mum-to-pop-her-court-shoes does not give him a right to be regarded as a greater authority than any opinionated know-all commoner you will meet in any pub. In fact, he is treading on dangerous ground for a would-be King-thingy because he is blundering into contentious public affairs and calling into question Government policy, which has approved controlled testing of GM spuds, which are now sprouting in Yorkshire.

Because he is 'Royalty', the princely pronouncement that GM food would be "guaranteed to cause the biggest disaster, environmentally, of all time" was trumpeted across the media. No matter that he did not produce any scientific evidence and ignored the fact that the subject is complicated by conflicting research, confused GM with cross-bred crops where there is no biological manipulation and dismissed Third World countries which have moved from dependence on food aid to self-sufficiency.

Prince Charlie is himself a walking anachronism, the embodiment of the quandary of monarchy: whether it has any value or is an outdated and vaguely ridiculous anomaly.

A combination of breeding and brainwashing appears to have convinced him that his contribution is important, even necessary, to the nation. He has said in his future role as King that "the most important thing will be to have concern for people and give some form of leadership". If the backward-looking Prince of Wails is a national leader, Britain is in worse shape than I thought.

Good or bad, we elect our leaders and if they are bad, we kick them out. The Royal Family do not have a divine right; they 'rule' in a strictly limited way only because we tolerate them – and because their titles confer on them a pseudo-celebrity that is handy for tourism and selling tabloid newspapers.

Ceremonial flummery has its uses as historical pageant and a tourist attraction but we should be careful other nations do not judge us by that, because the dressing-up too often topples over into unintentional satire. There is nothing more Ruritanian than the appearance of Charles or Philip and their male relatives on military-style occasions when they are converted into field marshal, admiral or air marshal by a quick change of uniforms, each dripping with gold braid and medals and none of which have been earned.

Nothing is more phoney – with the honourable exception of Prince Harry in Afghanistan – than the younger royals using the armed services as a convenient finishing college or time-filler until they graduate to the onerous duties of cutting ribbons and laying foundation stones. Does anyone really believe in Prince William as the hero of death- defying drugs busts in the Caribbean? No wonder they regard service helicopters as handy flying taxis to get them to society parties.

The parliamentary oath is a dire warningof things to come: "I swear by Almighty God that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth, her heirs and successors, according to law." It reminds us that, unless we come to our senses, we will be stuck with the House of Windsor indefinitely.

No one would dream of asking the present Queen to abdicate, but after her comes Charles, 60 this year and likely to be drawing his pension before the throne becomes vacant. What message would it send to an increasingly competitive, forward-looking world to have him become head of state in that state? And after him would come the controversially named King William, who has so far shown no talent for anything except picking good-looking women…

Those MPs who want to dispense with the oath should be encouraged and, while they are at it, let them look for a new national anthem that is truly national and dispense with the farce of the Queen's Speech: "My government will this, that and the other" in words put into her mouth by politicians and a lot of which one says through gritted teeth. Oh, and a referendum on whether we need or want class-ridden rule by royal relics.

Slowly and far too timidly, inch by inch, Britain has been edging out of the 17th century and into the 21st, but there are signs that the process of rocking the royal throne is speeding up. And, if we play our court cards right, we could be shot of monarchy and all the mumbo-jumbo that goes with it, sooner rather than later.