They know that badly divided parties are seen as ineffective and that well-resourced rival

They know that badly divided parties are seen as ineffective and that well-resourced rival parties will quickly spot any deviation in line between one frontbencher and another. Tony Blair was irritated by Clare Short saying something personal and sensible enough about taxation because he could visualise how the Conservatives and the Daily Mail would use it.It is hard not to sympathise. The trouble is, we all know that politicians in the same party disagree. These parties are, after all, great sprawling coalitions of opinion and interest. In the age of post-ideological politics, their internal disagreements, whether on moral issues, or Europe, or education, are bound to feature more. This is a constitutional doctrine intended to convey the mystical unity of "the administration" as something that is much more than a collection of individual politicians.

Nobody will be able to measure this subtle balance of interests or quite spot the moment of turn. (Maybe, at 9.23pm on 13 September 1996, on BBC News, Michael Heseltine says "old-style socialists" just once too often.)But it matters for how we think about collective cabinet responsibility, too. However, you must learn to evaluate what will be very subjective views and realise that what is important for someone else may not be so for you.Attend school open days. Eventually, there must come a moment when the "good" done to a party by the endless repetition of phrases is outweighed by popular boredom and cynicism. Whenever someone does say something unscripted, whether it be Kenneth Clarke's admission last year that the Tories were "in a hole" or Ron Davies' robust views on the Prince of Wales, you can hear half the nation suddenly stop and pay attention.This suggests that for unknown numbers of voters, mantra politics must be repulsive, and doing those politicians who practice it no good at all. Advertisers are increasingly using irony, absurdity, pastiche and flights of surreal wildness in order to break through the noise barrier.

Think of the car ads that make much of the product having four wheels and being painted all over with paint, except for the windows.In this world, cynicism about political messages and politicians' media evasion is very high; however outraged ministers may be by their occasional rough treatment on, for instance, Radio 4's Today programme, polls of listeners tend to side heavily with the frustrated, in-their-faces interviewers. Politics is a team game.What too many politicians have failed to see is that both justifications are slightly out of date. First, we are much more discriminating and cynical consumers of information than we used to be. "Guinness is good for you" - "It's good to talk" - "Dogs bark, cats miaow, Labour puts up taxes".

But the political argument used against Short and other speakers-out-of- script is, of course, the importance of collective Cabinet (and Shadow Cabinet) responsibility. Everyone signs up to the same things; everyone pretends to believe the same things; everyone says the same things. The simple, vivid message of the 1978-79 Winter of Discontent kept on working for the Conservatives long after Labour had conceded most of the Thatcher trade-union reforms. Repeated Labour claims that the Conservatives were intent on privatisation of the NHS hit home by repetition.