Geoffrey Robertson: Parliament's reform proposals don't go nearly far enough

"Like monkeys scrambling for nuts" seems a particularly apt analogy for British MPs presenting their expenses claims, although it was said by John Adams of the Continental Congress. As the mother of parliaments grows old disgracefully, its more advanced progeny have devised highly effective procedures for punishing errant politicians. It's time we took a few leaves from their statute books, because the vague reform agreed last week by all parties for a "parliamentary regulator" does not go far enough.

We might begin by finding a name for the kind of behaviour that has been exposed in the past fortnight. Submitting unconscionable expense claims to an office charged with adjudicating them is not, in most cases, "dishonest" (the test for a fraud prosecution), and the colloquialism "rip-off" hardly captures the scale of the greed that seems to have become a Westminster custom.

Although the English language has no word for it, the Australian language does: it's called a "rort" and what MPs have been doing is "rorting the system". This vaguely onomatopoeic word describes the calculated extraction of taxpayers money to which MPs are not entitled, but for which they will not be condemned, other than by public opinion should they be found out.

Britain needs a mechanism that will put a stop to "rorting," and not just by exaggerated expenses claims, and it must be a much more effective body than the milksop "Parliamentary Commissioner" whom MPs can remove if he or she becomes too inquisitive, or the clubby "Privileges Committee" with its arcane rules about acting "on one's personal honour". The all-party agreement to bring in some independent oversight is insufficient: the new regulator will deal only with expenses claims and will have no compulsory powers of investigation.

More advanced parliaments have found the answer in an institution called ICAC – an Independent Commission Against Corruption – based on a model developed in colonial Hong Kong to deal with bribery of officials. Adapted for investigating misbehaviour by elected politicians, it has proved a formidable institution in Australian states, bringing down Premiers and Cabinet Ministers as well as local councillors "bunged" by property developers. It is headed by an independent judge, staffed by lawyers and investigators, with compulsory powers to summon and cross-examine politicians and those who have allegedly crooked dealings with them. It has ample surveillance powers and can open any bank account.

The key to ICAC's effectiveness is its complete independence from parliament, its draconian powers to obtain information, and its reliance upon skilled forensic investigation rather than policemen. Faith in the capacity of the police to deal with political corruption is one of the great British myths of our time. The public demand to "bring in the plod" ignores the dire track record of our constabulary.

The real problem, of course, is that the Westminster system of government, as developed in the UK through establishment nudges and winks rather than pursuant to a written constitution, is wide open to corruption. The genial and gentlemanly "code of conduct" is easily side-stepped. There is no effective deterrent to "rorting".

In Britain, transparency has been a lengthy battle. Speaker Martin and the Head of the Fees Office fought tooth and nail to keep MPs expenses under wraps by contesting the Freedom of Information claim, which eventually led to their exposure.

And still, one feels, MPs don't get it. For all the outrage about mole traps and manure, nobody has yet noticed any problem with that utterly traditional practice whereby MPs are permitted to employ their spouses and children – indeed their sisters and their cousins and their aunts – in taxpayer-funded private offices. This is a practice called nepotism and it is a well-known form of corruption everywhere except Westminster, where it is long hallowed.

The all-party agreement to set up an "independent regulator" is vague. There are off-the-peg ICAC statutes downloadable from other Commonwealth parliaments (even Malaysia now has one) which should be adopted immediately. Parliamentary privileges committees should be abolished, along with all the parliamentary privileges immune from challenge in the courts. Unless an ICAC is up and running by the next election, we are in for the lowest turnout since the Barebones Parliament.

Geoffrey Robertson QC is Head of Doughty Street Chambers and author of 'The Tyrannicide Brief'.