So: those televised prime ministerial debates will definitely be happening in the runup to the election. The excitement is hard to contain: three separate primetime shows on Sky, ITV and the Beeb in which Brown, Cameron and Clegg will get the opportunity to talk and talk and talk and talk and talk. And possibly jig. But mainly talk.

Depending on your point of view, this is either a refreshing opportunity for politicians to connect with the electorate, or the least sexy hour of television since that Channel 4 documentary where they chopped up an elephant.

Even though its power and influence are in decline, TV still fascinates and horrifies politicians in equal measure. They're attracted by its potential to hypnotise and pacify millions, but repelled by its laser-like ability to magnify physical flaws or tonal cock-ups. It's like a magic amulet that can sometimes control the masses, but also might explode in the user's hand at any time.

Obviously image is paramount. On TV, no matter how eloquent you are, 75% of the audience can't even hear what you're saying: they're too busy making subconscious judgments about the tone of your voice or the angle of your lips. Conventional wisdom would have it that Gordon Brown is clearly at a massive disadvantage here, since he's slowly come to resemble a lumbering, doomy Mr Snuffaluffagus with all the carefree joie de vivre of the Kursk submarine disaster. But Cameron and Clegg are, if anything, a bit too telegenic, a bit too slick, a bit too clean-cut and heigh-ho. They've tried too hard to appeal in soundbite pop-up form: stretched over an hour, they may start to grate, their smooth appearances unexpectedly conspiring against them.

Cameron in particular looks like a boring dot-eyed "nice" neighbour from an underwhelming Christian soap opera. He's a replicant; an Auton; a humanoid; a piece of adaptive software that's learned to appeal to your likes and dislikes – "customers who bought Tony Blair also bought the following" – but inadvertently creeped you out in the process. Let's face it: if you discovered he doesn't have a belly button or any pubic hair, and spends one night each week lying semi-conscious, face-down, "recharging" inside a giant white laboratory pod filled with amniotic fluid, you wouldn't be entirely surprised. And voters are likely to sense that eerie unearthliness. He'd better stutter or fluff a few times, just to throw them off the scent.

But even if all three manage to flawlessly imitate human beings, defeat may still be snatched from the jaws of victory: if Nick Clegg spends the first 50 minutes rousing the audience with his fiery, lyrical rhetoric – as per usual – only to sneeze unexpectedly five minutes before the end, leaving a giant pendulum of mucus dangling off the end of his conk, the unfortunate mishap would be looped and repeated ad nauseam on every rolling news bulletin for weeks to come. He'd be Mr Snot. And do you want to vote for Mr Snot? No way. What if he sneezed on the nuclear button? He's out of the running. Which leaves you choosing between a haunted elephant or the humanoid.

(There are other parties you could vote for, obviously. But they're excluded from the debates and therefore no longer exist – a terrible blow for Nick Griffin, who was hoping to win over the public with his devilish good looks and impish personality.)

So: mammoth or android. Which is it to be? To help you choose, the news networks will doubtless offer post-match analysis of each nanosecond. Professional Westminster spods will deconstruct each sentence in search of hidden meanings, like scientists translating garbled messages from space. A body-language expert will discuss Cameron's eyebrows for 38 minutes. A fashionista will tell us who wore the best shirt. And every other citizen in the country will be asked to deliver their opinion via vox pop, email, tweet, phone poll or synchronised Mexican wave. Eventually a consensus will form regarding who won, at which point the lucky victor will be given the keys to 10 Downing Street, a fly-drive holiday for two courtesy of Virgin Atlantic, a five-album recording contract with Sony BMG, and an ITV2 reality show of their very own.

So terrifying-yet-alluring is the prospect of the debates, the parties have only consented to take part provided each broadcaster adheres to a series of 76 rules, drawn up in advance. Every aspect will be controlled, from the time allocated to each question, to the layout of the set – even the framing of audience cutaway shots is crucial. Presumably spin doctors from all three parties will be lurking ominously on the sidelines, ready to run in and kick the cameramen to death if their candidate starts looking too sweaty. You can already picture Andy Coulson in the wings, chewing gum and eavesdropping on the gallery audio feed, which has been illegally tapped by a private detective and routed directly into Andy Coulson's earpiece without Andy Coulson's knowledge.

Curiously, one thing that's left open to the broadcaster is the opening and closing credits. Rule 68 states that "each broadcaster [is] responsible for their own titles, music, branding etc". If I was running ITN – which, at the time of writing, I'm not – I'd make the most of this sole crumb of freedom by creating an insanely inappropriate title sequence in which a claymation Brown, Cameron and Clegg take turns performing sex acts on a cow, a kettle and a hole in the ground, all of it backed by the old It's a Knockout theme tune. Then it abruptly cuts live to the studio, where all three leaders have been waiting to speak, watching with mounting horror as this sickening cartoon unfolded on the monitors. As they storm out, a body language expert analyses their facial expressions, and the studio audience waves giant foam hands around. It might not affect the election either way, but who cares: that's entertainment.