It's incredible that this mediaeval nonsense still applies in Australia.
MORE than two centuries ago, Tom Paine famously pointed out that a hereditary monarchy was as absurd as a hereditary poet or hereditary mathematician (today he might have added hereditary airline captain). But his republicanism failed to take into account the enormous entertainment value of the royal family, currently on display. The palace's decision to censor the Chaser strikes at the very heart of this continuing value of the monarchy for Australians. Why else should we be reigned over by a white Anglo-German Protestant monarch?
The bedrock of the Australian constitution - the law which defines our head of state - is the 1701 Act of Settlement. It is a blood-curdling anti-Catholic rant that enshrines Protestant religious beliefs in the succession to the throne. This means that any monarch who holds communion with the Church of Rome or who marries a Papist - heaven forbid a Muslim or Methodist or Scientologist - is immediately dethroned. The act imposes anti-meritocratic race discrimination: no one unrelated to this German family (the Windsors changed their name from Saxe-Coburg Gotha during the First World War to disguise their familial relationship with the Kaiser) can aspire to the crown.
This primitive law adopts the feudal principle of primogeniture (inheritance down the male line), so that if the happy couple produce a daughter, she will be relegated to the bottom of the stately pile, below any subsequent male heirs. If Charles III were to convert to Catholicism (or have a sex-change operation), the crown would go to his male children, then to his male brothers and their families, ahead of their older female sister.
There is still the 1351 Treason Act, which did in Anne Boleyn and will constrain Kate, with a legal chastity belt, after Charles becomes king: it punishes (until recently, with death) any party to adultery with (and including) the wife of the heir of the throne. Incredibly, this mediaeval nonsense still applies in Australia.
These constitutional laws are obsolete and obnoxious, and in some cases very silly. For example, ownership of every wild swan is vested in the monarch, and in the case of ''the royal fish'', the head of every whale, sturgeon or grampus landed in the United Kingdom (it is not clear whether this law extends to Australia) belongs to the king and their tails belong to the queen. The monarch is entirely immune from legal action - which would be tough luck for any tourist who happened to be run over today by a royal motorcade hastening to get to the church on time.
Why has reform not seriously been attempted? Tony Blair's government claimed it would be too hard, because the Commonwealth would need to be consulted and countries such as Jamaica and Australia were besotted by royal tradition. But Commonwealth countries do not need to be consulted at all: if they still wish to be reigned over by the British royal family, they must take it as they find it, after it has moved into the 21st century. Prime Minister David Cameron is to legislate next year, because Britain is subject to the European Human Rights Convention, which requires the elimination of sex discrimination in public office. There is nothing that Australia can do about it.
It is an open secret at the Commonwealth Secretariat that they do not want Charles III to be the next head of the Commonwealth when the Queen retires - they are looking for someone more inspiring. Mandela, once the favourite candidate, is now too old.
But there is an even better candidate whose name is being mentioned as an alternative to Charles in due course, namely, ex-President Obama, with his Kenyan ancestry (as some believe, Kenyan birth). There are rumours that the palace's refusal to invite him to the wedding was neither oversight nor overslight, but a fear that Barack and Michelle would appear to the ''black Commonwealth'' as superior to Charles and Camilla as future leaders of the Commonwealth.
In the meantime, where stands republicanism in Britain? There has been little intellectual advance since Cromwell's short-lived republic from 1649 to 1660. Some years ago, I devised a legal campaign for The Guardian newspaper to challenge the monarchy - it had initial success when the House of Lords judges said that the unrepealed sedition laws that sent Irish republicans to Botany Bay in 1848 could never again be enforced, thanks to the Human Rights Act. But we could not find a Catholic in line to the throne prepared to challenge the discrimination in the Act of Settlement. Although there are many (mainly German) in the first 1000 in line for the throne, all those contacted declined the opportunity to bring a test case because they feared they would no longer be invited to take tea at Buckingham Palace.
As part of that campaign, there was a discussion about how to elect a republican president and ensure that political lobbying did not put some spent party hack on the constitutional dais. This could simply be avoided, were the 1701 Settlement Act to be replaced by a law requiring democratic election for the head of state every five or seven years, but excluding from candidature anyone who has held government office. That would, of course, permit Prince Charles to stand - he would probably win the first presidential election unless a royal vote was split by one of his sons (or his sister) standing against him. That might let in Richard Branson or Helen Mirren, or lead to victory for the inevitable ''Stephen Fry for Queen'' campaign - but why not?
It is unlikely that British changes to the Act of Settlement will cause the monarchy to unravel in this way. But some will certainly be made, before the birth of the heir who will reign over Australia after William V - in about 2060. And they will be made whether Australia likes it or not. Is this the kind of independence of which we can be proud?
Geoffrey Robertson is a Queen's counsel and author of The Tyrannicide Brief.