Elections everywhere. Tomorrow, the first round of the parliamentary contest in Italy. In a month, Israel votes, which helps to explain the intensity of Operation Grapes of Wrath. In June, Russia elects a new president, quite possibly a Communist. Later in the year, the American public chooses between Bill and Bob - as well as taking part in the biannual returns to Congress. Here, Tory mortality and Northern Irish events permitting, there could be a general election within months.

The common denominator in those elections is party. Advanced societies are fissiparous, more diverse, less class bound, washed by the tides of trade and culture we handily label globalisation - yet we still seek to organise our government on the closed and sectarian principle that party represents a block of interests. In such a mobile, flexible, shifting society, there ought to be a multitude of parties. Instead, what we have is the old Anglo-American duopoly. Even that duopoly cannot escape the forces of change. Instead of a multiplicity of parties, we have parties with a multiplicity of splits, factions, internal divisions. Running any large party these days requires organising unruly, shifting coalitions, quite frequently involving some stray members of other parties. That is the lesson both John Major and Tony Blair should draw from another week when divisions within parties were more politically potent than divisions between them.

This week's conventional wisdom says party leaders should loosen up, admit dissent. People are mature enough to appreciate backchat in the ranks. Voters quite like it when Clare Short unbuttons her lip not because they want the new Labour double-decker to topple over but because stifled views make for immature politics. One of the things we most want to know from Tony Blair is how much a new Labour government would tax us. It is one of the things he least wants to talk about. Labour's stress on collective discipline parallels the Tory line in the Eighties that you had to make the state stronger to make it smaller; the new Labour line is you need to make the party more illiberal to take the country in a more liberal direction.

As for the Tories, Wittgenstein is Central Office's pin-up philosopher, with his principle that you have to be silent about the things that cannot be said. Europe is their great unspoken. Some say the Tories have always ridden two horses - free-market liberalism and authoritarian conservatism. Like an accomplished circus performer, the rider sometimes seems to be about to plunge into the sawdust but ends up straddling the rearing beasts, hat off, waving to the crowd. They are not alone in being split over Europe. Labour is just as split and even more silent about its Euro-divisions, according to a survey last week.

The Liberal Democrats too have issues on which they prefer to keep their counsel. Drugs is one. Beards and Fair Isle sweaters the leadership can live with, but it is not keen on open debate about legalisation of prohibited substances. Yet out in society drugs is a totemic issue. Attitudes towards drug use and classification link with generation, education, family experience, region.

So we have a situation in which issues that are hotly debated in the country at large - whether Ecstasy is safe or deadly, whether a single currency is good or bad - are met with a wall of silence from much of the political class, one of whose jobs is to test arguments in public debate.

The result is not just suppressed politics. Worse than that, elements of dishonesty creep in. Lines are peddled over and again not because they are believed but because they are the line. So arguments are not tested in the open. As a result, policies are vulnerable to being suddenly exposed as unworkable or misguided. The suppressed political debate about drugs gets expressed intermittently, often by people outside the game. Those inside are too busy biting their tongues to provide even a bite of sound.

The trouble with our current parties, obsessed as they are with internal discipline and the authority of leadership, is not that they are too tight but that they exist as they do. The sight of an Alan Howarth "crossing the floor" is ludicrous. He has not converted to socialism, the Labour leadership does not believe in it. He does not come from any of the social groups historically identified with Labour. It's just that Labour offers a slightly more comfortable home. Alan Howarth ought to join with Emma Nicholson in the Torbay and Stratford-upon-Avon nice persons' party, softish, intelligent and probably representative of a wide swathe of middle England.

What would a party system look like that was more representative of the diversity of our society? It might embrace a graduates' party (its future numbers assured), an urban singles' party and possibly - in an age when the very identity of many younger people is taken from their leisure pursuits - a party-goers' party, a retirement party, an anti-downsizing party.

One objection to going too far down that road, driven on by proportional representation, is Italy's chaotic and corrupt politics. But aren't fragmented Italian parliamentary politics more honest than ours? Italian politicians, on the floor of the chamber and in the senate, berate concentrations of media ownership, argue forcibly for welfare and pensions reform, being open and honest about regional disparities in wealth and earning power.

Party reform means parliamentary reform. Root and branch reform of the Constitution has, for the first time in generations, become a political possibility. As partisan identification with parties has weakened, respect has grown for independence of mind, the prized quality we want our judges, our teachers, children, civil servants and scientists to possess in spades. We need a party system that will ensure greater independence of thought and argument, while bringing out into the open the reality of government through coalition building.

This isn't completely beyond the bounds of possibility. Europe may yet drive a wedge through the Tory party. English nationalism in both Labour and Conservative parties may be inflamed by devolution to Scotland. New Labour will soon find its internal divides over tax, to name just one issue. However, it is highly unlikely that new parties will emerge and it is most likely that the factions will stay together behind their facades of party unity. The reality will be that party politics will be much more like Italy's chaotic coalition building - without the open argument - than we might realise. Our leaders know that, even though they don't like to admit it.