Much heat but no light at the Palaver on Pacific Quay

As Mrs Merton-style heated debates go, you could have fried chips in the Scotland Tonight clash between Nicola Sturgeon and Johann Lamont at Pacific Quay. The Deputy First Minister and the Scottish Labour leader were taking part in the fourth in a series of televised debates. Between the two of them, they managed to make the average viewer wonder if these occasions should ever happen again, or, at the very least, be postponed until the nation's ears have stopped bleeding.

The evening began promisingly. True, there was a minor hiccup when it emerged that Ms Lamont and Rona Dougall, the presenter, turned out to be wearing the same outfit of black trouser suit and white top. Awkward, but in Borgenesque Scotland we don't fuss about such trivialities. It was a telling sign, though, that someone, somewhere, had not thought this event through.

The first section, with Ms Dougall as the inquisitor, was civilised enough. It was in the second section, where the politicians were allowed to question each other, that matters took a turn for the Italian parliament. Voices were raised, dismissive remarks traded, and scowls exchanged. It was loud, unappealing, and about as illuminating as a two-watt bulb. The finest moment came when the cameras cut to another part of the studio where the menfolk, presenter John MacKay and two political journalists, were waiting. You will have heard of the 1000-yard stare of the traumatised Vietnam veteran. Here we witnessed the Pacific Quay five-mile ponder. One day these men would speak of what they had witnessed, but for now they confined themselves to muttering that they had not learned a lot that was new.

It was not supposed to be like this. On the back of the perceived success of televised debates in the 2010 General Election the Scottish referendum campaign was meant to be the arena in which the format could come into its own. There were national broadcasters with airtime to fill, politicians keen to get their messages across, and an electorate with an appetite for information.

So what went wrong this time? It would be sexist nonsense to say that the problems stemmed from the fact that the protagonists were women. The only difference between Ms Sturgeon and Ms Lamont and two male politicians was in the pitch of the voices. Well, women are here, they have higher voices, get used to it. Nor could one say, as in previous debates, that the encounter was one-sided. Both politicians gave as good as they got, both had their arguments ready. This was a meeting of equals, but it was also one that kept the viewer and the voter out in the cold. It was good television, in as much as it got people talking, but it was bad for democracy, a turn off for the common man and woman.

One could blame Jack Kennedy. It was, after all, his 1960 televised clash with Richard Nixon that started the debate myth rolling. Before an audience of more than 60 million, the young pretender to the presidential throne was widely held to have trounced the Republican vice-president, making him appear shifty and tired. Thus, the story goes, the tectonic plates shifted and the election was won. Yet the impact on the polls was only ever slight, and over the course of the four debates the viewing figures dropped substantially. The popular vote, when it took place, was close. But a legend was born, one that television was only too willing to fuel for its own reasons. Televised debates, it was argued, tested the mettle of a politician and brought the campaign into the nation's front rooms in a way no other medium could manage. They took politicians out of their comfort zone, made politics "real", and therefore more exciting. Or so it was thought.

Yet a televised debate is as manufactured a piece of machinery as a car engine. Before the camera encounters might have offered politics in the raw in the 1960s but by the time debates arrived in the UK they had long been primped and preened to within an inch of whatever life they had left in them. How could they not be given that the rules are agreed by the parties and broadcasters beforehand, and more rehearsals take place than for the average West End show? And what sort of test is it that the likes of Nick Clegg can triumph in?

A splendid account of where this branch of political theatre is today can be found in Double Down, the latest inside account of a presidential election by Mark Halperin and John Heilemann, the authors of Game Change. Between them, the writers lay bare the enormous amounts of energy and time that went into preparing for the 2012 presidential election debates and managing the aftermath.

Barack Obama was never a fan of the format, feeling it was all show and no proper political business, and he made this abundantly clear in the first debate in Denver. Yet as much as Denver made headlines, with some predicting the race was over for Mr Obama before it had started, in the long run it had no significant impact on the result. That presidential election, like our referendum, was about so much more. The battles that mattered took place not on the airwaves but on the ground, street by street, constituency by constituency.

One can see why so much emphasis has been placed on debates in this referendum. They seem an easy answer to the difficult question of how to inform millions of voters about complex issues. But not for the first time, the accepted rules of the game do not apply. The Civil Service, for example, might have been thought to be a repository of impartial information, but as has been seen from the papers coming out of Whitehall, and the Scottish Government's own White Paper, both sides are able, with some justification, to accuse the other of bias. When one part of the Civil Service sees it as its job to defend the policy of the government of the day in Westminster, and the other holds the same view in Edinburgh, clashes and confusion inevitably result.

The allure of the great debate is not going to go away any time soon. There is still the biggest prize, a Cameron-Salmond clash, to be won. In the meantime, there will be more of the same kind of shouting match that took place this week. But changes are required, starting with the ditching of politicians cross-examining each other with the emphasis on "cross". Any questioning should be done by those who do not have dogs in the fight: either political journalists, voters, or preferably both. Even better, get out of the studio and find out where the real debates are happening. As the Palaver on Pacific Quay showed, this referendum is far too important to leave to politicians alone.