Tim Walker: 'Millions watched Margaret Beckett torn limb from limb in Grimsby'

The Couch Surfer: It may be a form of direct democracy, but the function of Question Time is rarely to inspire reasoned debate

If there's one thing almost (almost) guaranteed to make me feel sorry for an MP – a pretty unlikely sentiment, I know – it's Question Time. It has a nature documentary's appeal; David Dimbleby's wry asides stand in for David Attenborough's commentary, while the crowd of big cats chews on some unfortunate, pinstriped zebra.

It may be a form of direct democracy, but the function of Question Time is rarely to inspire reasoned debate; it's to give members of the public an opportunity to shout at politicians without said politicians being able to back into their ministerial limousines waving and grinning inanely.

Ten days ago, 3.8 million viewers tuned in to see Margaret Beckett torn limb from limb in Grimsby – 400,000 more than in 2003, just after war was declared on Iraq. And last week the BBC brought the programme forward to 9pm to capitalise on the bloodlust.

A few years back, all an audience member had to do to elicit a round of applause from his or her fellow cabbage-throwers was sprinkle their indignant questions with one of a series of keywords: "Bush", "Oil", "Poodle", "WMDs" and so on. Over the next six months, standing ovations will be awarded to anyone who yells "hanging basket!", "trouser press!" or "ginger crinkle biscuit!" loud enough to be picked up by the roving microphone.

It's disconcerting when the only person on a panel to escape the attacks of the morally outraged is a chief executive of McDonald's, as was the case with the Grimsby edition. Even the man from the Telegraph, whose newspaper gave us this wonderful excuse to be outraged in the first place, got booed – for refusing to reveal the vast sum his employers presumably paid for the information.

The crowd tittered loudly when David Dimbleby suggested Beckett had been "fingered" by the media. I tittered, too. But then I had to close my mouth and swallow to prevent my dinner coming back up.

In Salisbury on Thursday a bumper panel of six – including squeaky-clean minister Ben Bradshaw, squeaky-clean Lib Dem Vince Cable and squeaky-clean Conservative William Hague (as well as Martin Bell, who's so squeaky clean that he hasn't felt the need to change his suit for about 15 years) – faced an audience who'd had a little more time than their Grimsby counterparts to focus their outrage into serious questions. Cable, Bradshaw and Hague had the good sense to defer to their accusers, rather than tell them, as Beckett had, that they simply didn't understand her poor colleagues, their duck houses and their dinners at Quaglinos.

In every Question Time audience you have the incorrigible shouters; the deep thinkers undone by nerves; and the people who want to be on telly, but don't have anything useful to contribute, so end up spouting a whole bunch of nothing and having to be cut off by Dimbleby in the middle of a six-part question.

But then there are the cabbage-throwers who cut to the quick – either by dint of having done sufficient research to visibly unsettle their target; or simply by capturing, coherently, the mood of the masses. Over the past couple of weeks, they've frequently been Lumleyesque ladies whose middle-class mores are temporarily toppled by the fact that they're so very, very angry. Hear them roar! (Like imagining oneself into the Big Brother house, I often wonder whether, were I a cabbage-thrower, I'd contribute something lucid and sophisticated to the debate. In truth, I'd probably break into a cold sweat, stumble over my words, and eventually resort to a cry of "patio heater!" or similar.)

The BBC is always asking its viewers to vote in pointless news polls, email our snow day photos, tell it what we think about, like, stuff. But Question Time remains the only televisual forum in which our leaders actually have to sit and listen to the led, however banal or brilliant their questions.

At times like these, the only interviewer a politician fears more than Paxman is the people, lots of people; angry, unpredictable, unabashed – and ungoverned by any stringent BBC guidelines.

Most of the time, the vast majority of the electorate lies back and lets its party or constituency representatives bat the issues back and forth among themselves in the House, or on Newsnight. It's uncommon that the entire political class finds itself in opposition to all the rest of us.

But suddenly Question Time is the most vital current affairs show on television again because, just as in 2003, it's the only one where the masses and their MPs meet, in public, to slug it out.