What were they thinking?

Today's events were topped off by a new YouGov poll showing Labour at 31% - just 9 points behind the Tories - part of the trend since the party conferences last autumn, where we've been slowly clawing our way back. We need around 34% to be able to be in with a shout of forming a government.

Amid this trend, and with the public recoiling from the giant airbrushed David Cameron pictures unleashed on them, why on earth did Patricia Hewitt and Geoff Hoon suddenly decide to mount a coup?

It wasn't just Labour members who were taken aback, backbench MPs were irritated too. So why did they do it? If they really believe that Labour is heading for defeat, why not let Brown take the hit, and then go for a full-scale leadership election after the general election? The clue was in their belief that a change of leader could happen within just 21 days, decided by the PLP and with a single candidate. In other words they are afraid of Labour's electoral college.

Labour is structured differently to other parties. A full scale leadership election involves having to win a majority across three electoral colleges - the PLP, the constituency members and the affiliates. In this post-financial meltdown world, I can say with some confidence that the chances of the membership and affiliates electing an arch-Blairite are slim to non-existent. The party will either go for a clean unifying moderate who is not part of any faction, someone like Ed Miliband, or the party will go left.

This means that the only chance for a David Miliband or James Purnell to win is to stage a coup where it's all decided by the PLP. The coups keep failing for the same reason - because they are being staged by the arch-Blairites. The PLP is not stupid. They don't really want to upset their activists, who do the leaflet delivery out of altruism rather than careerism. They can also see the dangers of having an arch-Blairite lead us into defeat (and if we change leaders we will certainly be defeated, simply for treating the voters like idiots with presidential/personality politics - voters don't buy this presidential business, they know that in the UK we elect parties).

Gordon Brown is actually a very important transitional figure in our party, a bridge between our past and our future. He's essentially holding the ring, holding it all together. If an arch-Blairite led us into defeat, there would be a reaction sharply leftwards in the leadership election afterwards. I'm sure this is why Peter Mandelson keeps defending Brown. If Brown toook the hit on behalf of the party, then it's likely a fresh moderate such as Ed Miliband would be elected by the membership. But the best way to keep Labour moderate and thus where the voters are, is for Brown to actually win the general election. That way when he retires, a moderate centrist has a very good chance of succeeding him. Governing keeps you moderate, opposition is when the loonies come out of the woodwork - see the 1980's for Labour and the early part of this century for the Tories.

The arch-Blairites kinda sorta know that their era is coming to a close, but can't come to terms with it. The irony about these repeated coups is that if some non-factional person with integrity staged them - someone like John Denham - people would follow. But who would follow a Geoff Hoon, or a Hazel Blears?