Joan Bakewell: Can political satire make politicians behave?

You have to laugh... you just have to laugh. In the face of all the contradictory and evasive nonsense of current politics, judicial criticism is all very well, but it leaves you hungry for something more hard-hitting, something that will sink its teeth into its target but at the same time give you a rumble of pleasure. That rumble, great volcanic eruptions of it, is currently provoked by some of the best television comedy for years. The noose of national laughter is closing in on Tony Blair.

On the day the Government set out its proposals to get heavy with disability benefit claimants, Shameless's Gallagher family were in full cry, cheating the benefit system, hiring out their children to pose as dependents in other families and thus con the bewildered investigators. Immediate comment, loads of laughter.

This brilliant series is a celebration of how a crazily dysfunctional family can through native wit and resourcefulness outflank the dull and charmless expectations of a sullen, regimented system. We don't want them as neighbours, and we hope they get out of the Chatsworth estate. But then one of them did: the Gallaghers' creator, Paul Abbott, claims they are based on his own family. And look at him now. So there is hope.

The previous night's television mocked the politicians supposedly in charge of the system that produces the Gallaghers. Armando Iannucci's The Thick of It is this century's equal to Yes Minister, and equally mired in contempt for the political process. We watch in all-too-ready belief as Hugh Abbot, the hapless Minister for Social Affairs, is mercilessly manipulated into public humiliation by a foul-mouthed Number 10 enforcer. Iannucci is aiming beyond laughter, landing bruising blows on the public's already damaged regard for politics and politicians. "I have become," he says, "increasingly appalled by how the truth is quite unashamedly contorted in political debate." Shameless, in fact.

These masterly critiques of our times are currently on Channel 4 and BBC 2 respectively. On Tuesday, in his inaugural lecture as this year's Oxford Professor in Broadcasting Media, Iannucci explained why this is: it seems the commissioning process takes fewer and fewer risks with new ideas for the big mainstream audience channels, while letting BBC 4 and 2 and Channel 4 keep the most daring and challenging stuff for where it can't offend the mass audience. Broadcasters are playing safe, keeping challenging stuff for minority channels, perhaps hoping the biting satire won't infect the entire nation with hysterical laughter as it recognises en masse the truth of what it sees.

The question is, does laughter have the power to change things? Voltaire might think so. France certainly did. It was so fearful of his lacerating wit that it imprisoned him twice in the Bastille, then drove him into exile. The sheer abundance of his lifetime's writings, together with the social renown attendant on his wit, must surely have created a mood that foreshadows change, and pretty radical change at that.

Jonathan Swift was another whose vicious attacks entered the political discourse of his day. His 1729 essay "A Modest Proposal" suggested that, as a cure for the Irish famine, the peasantry should offer up their children as food for the rich. Think what his vitriolic pen would make of the current newspeak around "extraordinary rendition". In the 1960s, Ned Sherrin's ground-breaking That Was The Week That Was certainly stirred things up, tolling the bell on deference for ever. Yes, laughter can help to change things.

Today, it is both difficult to make the same impact - so many papers, so many channels. And we have learnt over decades to be resigned to the venality of public life, the vanity of power. It was there in Channel 4's account of Tony Blair's pop star ambitions. Commenting on the Prime Minister's skill as an actor, his former tutor described Blair's speech at Princess Diana's funeral as "like a performance by an old actor who lost his real passion for acting but could still remember his technique".

It was there in the parade of idiocy that Big Brother elicited from George Galloway. Laughter at such antics might change things a little. It might lose George his parliamentary seat. Yet there's no sustained impact. Between the days of Yes Minister and The Thick of It, ministerial behaviour seems only to have got worse. At the same time, the public have got more knowing, more cynical, and slowly, the tide of mockery - while glancing off the thick skin of individuals - is threatening the whole political edifice itself. It won't be easy, when the day comes, to restore trust and confidence and truth in public life. Mean laughter, as always, eases the pain of living.

As I say, you have to laugh.

joan.bakewell@virgin.net