Leading article: Debates could be the tonic our electoral politics needs

The next general election, whenever it is held, will bring Britain into the modern age in one crucial, and welcome, way. The leaders of the three major national parties have agreed to meet in a series of televised debates, as their counterparts have done for many years in the US and latterly in Europe. Electoral politics will finally come into voters' homes in a way it has never done before.

It could be said that this will not be as revolutionary an experience for Britain as it has been for other countries. The weekly joust that is Prime Minister's Questions means the head of the Government is regularly challenged in the Commons. The BBC's Question Time and the British style of political interviewing, some of the most aggressive in the world, have ensured a media presence for undiluted politics.

Yet there is nothing quite like a televised electoral debate. At Prime Minister's Questions there is a clear order of precedence, in which the Liberal Democrats very much take third place. Any procedural rules – and reams of them will be hammered out between now and then – will ensure that all three are treated equally.

But the main reason why televised electoral debates have no parallel is because the stakes are so high, and no amount of preparation can guarantee the outcome. While some encounters can be lively, others tetchy, and others even tedious, there are also those that have transformed the larger contest. The first US presidential debate, Kennedy-Nixon, is the most renowned, but it is far from the only one to have helped determine the result.

Anticipation of a decisive moment is one reason why election debates attract audiences. But they also communicate something about the candidates that may not be conveyed any other way. The interest such debates command also offers at least part of an answer to voter apathy and cynicism which makes Britain's first election debates particularly well timed.

The current state of political play also explains why all three leaders have agreed to take part, when even so capable a modern politician as Tony Blair rejected the idea out of hand. As the underdog, Gordon Brown has nothing to lose, and perhaps something to gain, from his wealth of experience and serious demeanour. David Cameron, for the Conservatives, has a chance to show off his undoubted mastery of the medium, while trying also to prove that he has substance. And Nick Clegg, for the Liberal Democrats, gains a forum that will place him before a national audience on an equal footing with the other leaders.

There are always objections that can be raised, and Alex Salmond for the Scottish Nationalists is first in the queue, threatening legal action against his party's exclusion. Plaid Cymru, the Greens and Ukip are also calling the debates undemocratic. But even three participants in a debate can be a crowd, and the wide gap in national support between the major parties and the others is justification enough.

More generally, it is argued that televised debates have no place in a parliamentary system, where voters do not elect a national leader directly, and only foster an unhealthy personalisation of politics. The response must be that debates have done no harm to other parliamentary systems and today's politics is already highly personal. At home and abroad, televisual skill is an asset for a politician. There is no point in lamenting a supposedly purer form of politics. Televised debates could be just the tonic British politics, and the jaded British public, need.