This is how it works these days. David Cameron wanted to establish that Tory economic policy was completely different from Labour economic policy. And that when it all goes horribly wrong over the next year, it won't be his fault.

So he started on the Today programme. He wasn't to know that he would get a particularly challenging interview from Evan Davis, but no matter. He'd made his point.

Then it was on to the LSE in London for a speech due to start at 10.05am.

A curiously precise time, but there was a reason. The 24-hour news channels, BBC and Sky, have headlines at the top of the hour. These are generally finished after six or seven minutes, which meant they could, if they wished, go live to the Conservative leader.

So at precisely 10.05, almost to the second, he strode out onto the stage.

Peter Sutherland, the LSE's chairman, introduced him. That left one minute for a little joke: "My daughter was asked what I did by the deputy editor of the Times. She said, 'My daddy reads the newspapers for a living. Sometimes when I'm watching cartoons on television, he switches over and watches himself instead'."

Short but appreciative chuckle, which brought us to 10.07 precisely. Lights! Action! Soundbites! All the bullet points of the speech were in the first few moments: "Clear choice ... great economic problems that confront this generation ... Labour argues that debt is not a problem and can be dealt with by unspecified people at some unspecified time in the future ... by contrast, the Conservative response ..."

By this time we had reached 10.09, and that's when the editors in Wood Lane and Osterley would be getting antsy. There might be another battered child in Haringey, or a ban on cigarette displays, or exciting footage from the Irn Bru Scottish third division. So after that, it didn't much matter what he said, except that he got it on to the record.

And it was pretty apocalyptic stuff. The government's plans were "useless" They shouldn't just suffer, "they should be punished for a generation for their economic crimes," he said.

We were going to be borrowing some £4,000 for every family. Britain would be in the red until 2016, "and that is on an incredibly optimistic forecast. Labour has spent it. Labour has blown it." (He loves the demotic. You can't imagine Leo Amery telling Neville Chamberlain in the Norway debate: "You're useless, you are. You've blown it.")

Where one begins to lose him is when he retreats to generalities. He says that the first step to economic recovery is "to fix our broken society".

He makes it sound like something you'd pop on the back on an envelope. "Buy milk, phone babysitter, fix broken society" as if it was a DVD player that needed repairing.

You can imagine the conversation: "Oooh, I dunno. I suppose I could fit you a new motivator, but frankly, with prices what they are, you'd be better off buying a brand new society ..." Then we got onto "empowering individuals", "coherent public service reform", the "new, post-bureaucratic age" and "unlocking the potential of private and voluntary sectors", and we realised that he had little to offer except intangible Blairish aspirations. But it didn't matter. The news channels had long moved on.