David Cameron's speech in Blackpool today was a "tour de force". I defy anyone not to be impressed by someone who can make a speech without notes for five minutes, let alone an hour. It's not that they teach you to do that sort of thing at Eton, but they teach you to have the self-confidence to think you can. But did it amount to much? One of my colleagues at the New Statesman said it ws like watching a dog standing on two legs (impressive but essentially unedifying).

When I arrived at Tory party conference in Blackpool on Sunday, I spotted Cameron scuttling through the Imperial Hotel looking like a shadow of his former self. He has lost a lot of weight and Tories I spoke to were worried about him. But he looked a lot jollier on the platform and by the end of conference he had clearly pulled himself together.

Brown is now fizzing. His speech, like Cameron's was an amalgam of personal anecdote and right-wing rhetoric. But its delivery betrayed his more humble class background.

So Cameron is posh and Gordon is not. This is not as banal as it sounds. I now have no doubt that the election will be fought on class grounds. The policies won't give this away, but behind the scenes, the Brownies hate Cameron for being a toff and the Cameroons despise Brown for being an oik.

I don't know how often in recent months I have heard Labour MPs say: "They just think they are born to rule." This sort of language was not permitted during the Blair era. If an election is called next week then I have no doubt class war will break out. Despite (of perhaps because of) the apparent ideological proximity of the two parties, this will be the most tribal elction since the 1980s.