Colin Philpott: The great debate – will a TV clash have the power to sway voters?

British voters will, for the first time, see live debates between the party leaders on their television screens. Also, when voters consider where to place their crosses on the ballot paper, the Sun will be shining on the Conservative Party and not Labour for the first time since 1992. But how important will these traditional media be in determining the outcome, or will the web and social media play a crucial role?

Considering that Britain sees itself sometimes as the birthplace of modern democracy, it's pretty shameful in my view that our political leaders have refused until now to submit themselves to the scrutiny of live television debates. I happened to be in the US during the later stages of the 2004 (Bush-Kerry) campaign and the debate was a focal point and there was considerable interest in it.

I am pretty certain that the debates – how about Strictly Come Politics or maybe The X (as in cross on the ballot paper) Factor for titles? – will attract significant audiences here in Britain. When Nick Griffin was

on Question Time recently, almost eight million people tuned in – far higher than a normal edition.

Despite widespread cynicism, people are still interested in who governs them and we all like a bit of theatre. How likely is it though that anything that happens in the debates will actually affect the outcome?

The rather boring truth is that most politicians will probably approach these debates defensively, like a football team trying not to concede a goal, and we may end up with a series of no-score draws which leaves the political league table pretty much where it was before. However, there is a chance – just a chance – of a gaffe or a slip-up which could electrify the campaign.

It's important to remember that the most celebrated media moments where politicians have been wrong-footed during election campaigns have been when they've had to deal with "real" voters not professional interviewers – Margaret Thatcher over the Belgrano sinking after the Falklands War and last time round, Tony Blair on the health service.

But image matters and television is all about image. The outcome of the next election will be determined by the votes of a few thousand swing voters in up to a hundred constituencies at most, that is to say, not that many of us. Those floating voters will be swayed in part by their perceptions of how the parties will or won't serve their own interests, but also by image. "That David Cameron – seems like a nice young man"; or "Gordon Brown – a bit dour but not as flash as the old Etonian toff".

And what about the good old Sun? It amused me how pompously they announced how, after due consideration, they had decided to switch

their allegiance from Labour to the Tories as though the whole of the electorate was waiting for this to happen.

Critics claim it's not a principled decision but either

a case of backing the party they believe is a likely winner,

or the result of a deal by David Cameron which will enable the Murdoch media empire to advance its business interests through a benign regulatory system under a Conservative government.

Whatever the reasons for the switch, I am doubtful that it

will make an enormous difference. The Sun has a lot of readers and it must have some influence but how seriously do most people take it? People buy newspapers which confirm rather than

shape their prejudices and opinions.

So what of the role of new media? The web is transforming our lives and society and it will play a role. Firstly, the internet is very good at spreading campaigning messages quickly. So there is the possibility of something – maybe on a single issue – spreading like a bushfire across the web and disrupting the carefully stage-managed messages the parties are trying to put across.

And, of course, the web means it's now so much easier to dig up stuff from the past.

So skeletons in a candidate's cupboard (or rumours thereof which might be completely untrue) and reminders of what someone once said on an issue which appears to contradict what they're now saying – all these are now more readily accessible because of the web.

So, as we come to ponder how to exercise our democratic rights, the battle for our hearts and minds will be influenced by all sorts of media messages and images from even more sources than before. But no single media will be dominant in determining whether Gordon Bown or David Cameron is handed the keys of Number Ten.

Colin Philpott is director of the National Media Museum in Bradford.