Every year when the Budget comes along, the web is taken over with high quality calculators, which are fun and let you know exactly how badly you’re going to get screwed come the new tax year. It’s not a pleasant thing to know, but it is useful.

So I was intrigued to see that your mate and mine, Ken Livingstone, had brought out a calculator of his own. Being a curious sort, I went and had a little look. And what I found was not a calculator but a slogan generator. Admit to travelling by train and you get told Every fare payer can save an average £250 every year for four years through Ken’s 7% fares reduction pledge. Admit that your household pays energy bills and you are reassured You can save an average of £120 every year for four years through the all-London bulk energy purchase scheme.

Here’s the thing: I don’t believe that first slogan – the idea that an ambitious politician like Boris Johnson is sitting on a billion pound pot going into an election and has increased fares instead is ludicrous. And I don’t credit that second one either; I’m too much of a free-marketer to think that a state sponsored buying group is anything other than a bad idea. In short, it’s not a calculator. And I don’t believe it’s just a slogan generator – it’s a bullshit generator.

That said, I don’t think that any of the candidates are much use. Just that each and every one of them are more use than Ken.