Rory's week: It was Kierkegaard who said you couldn't make it up. Or was it Littlejohn?

The conference season has confirmed in my mind that the real differences in British politics exist not between the political parties, but within them. I imagine at least a third of the front bench in each party could happily serve in an alternative government, even without the offer of a peerage.

It seems almost pointless trying to parody Tony Blair when David Cameron does it with such dedication. It will come as no great shock to students of Blair that Cameron should seek to define himself by attacking his own party’s core beliefs. The only surprise is that delegates are prepared to shell out so much for the privilege of being harangued. But then, sadomasochism always was the Tories’ favourite pastime.

Competing for the centre ground is clearly quite a strain: matching the rhetoric of Blair's "campaign socialism" drove the Tory leader to his greatest inanity yet: "Let sunshine win the day!" Obligingly, the heavens opened for the rest of the week. There was a further dilemma: how to match the pulling power of Bill Clinton?

I can reveal exclusively that the Tories looked into the feasibility of exhuming the body of Dwight Eisenhower to talk about the importance of letting sunshine win the day. Annoyingly, Eisenhower wanted to move on to talk about tackling crime in the 21st century, while the Conservatives wanted to stick with the sunshine angle. So Dwight was thanked for his co-operation and reburied.

I've commented here before about how reality has a habit of trumping any satirical fantasy. Last month I met a fully paid-up management consultant who had been busy asset-stripping in Slovakia. This involved selling off several steel mills and a couple of brothels. He told me with delight how the company arrived at a valuation for the brothels by using a mathematical formula based on the ages of the women who worked there. I think it was Søren Kierkegaard who said,

"You couldn't make it up." Or was it Richard Littlejohn?

And finally . . . after 16 months of these columns, I've decided to call it a day. Or at least an afternoon. The demands of writing and filming an hour's worth of TV in four and a half days, plus two children who recognise me more from pictures they see of Blair in the paper than from seeing me

in the flesh, mean it's time to take a break. It's taught me a lot about writing articles every week – not least that sometimes the best are the ones you start without any idea what you're going to write about.

Then, if I'm honest, there's the lurking worry that if I give my opinions, they won't be a barrel of laughs, while if I produce a barrel of laughs, it won't be serious enough. It's a similar dilemma on Bremner, Bird and Fortune, which at its best can be satirical, but is more often topical comedy and wouldn't claim to be particularly Swiftian, a thought I often have as I catch sight of myself in the mirror in a pair of tights and a fright-wig.

So much have modern audiences come to associate satire with light entertainment that it is easy to forget that real satire is often dark, bitter and uncomfortable; not exactly what Channel 4 is looking for on a Saturday night - unless you count Big Brother. And since the iconoclasm of the Sixties, it's no longer shocking to make politicians look stupid. It's become the norm, and the politicians are more than capable of doing it themselves. When doing a run of theatre shows last year, I found it interesting to see that if I ventured into more challenging areas, the audience grew less responsive. They'd come to be entertained, not lectured. Mostly they were looking for a Blair impression that would make them laugh. No wonder Cameron is so popular.

The next "Bremner, Bird and Fortune" is on Channel 4 on 21 October at 8pm