Today’s ICM poll in The Guardian showing the Tories with a record 20% lead over Labour will increase the pressure on Gordon Brown.

Conventional wisdom – backed up by the results to date of the latest LDV poll – suggest the Prime Minister is safe for the moment. And at least part of the reason for that is the absence of a popular alternative – perhaps David Miliband, Alan Johnson, Harriet Harman or Jacqui Smith might do a better job. But no one in the cabinet has yet demonstrated they have anything like the chutzpah that would be needed to turn around Labour’s dire poll ratings.

So I was intrigued by John Rentoul’s leadership speculation on The Indy’s Open House blog today bigging-up Work and Pensions minister James Purnell, and highlighting his recent speech to Labour’s Progress Challenge in which he launched a more plausible attack on the Tories than Mr Brown’s ‘clunking’ efforts have so far mustered:

There is one aspect of the Tory sales pitch I agree with. Cameron has said many times that we shouldn’t judge him on where he’s come from but where he’s going. Absolutely: I couldn’t care less where he went to school or who his parents are. It’s where he’s going that worries me, not where he’s been.
Because I don’t think, in his heart of hearts, he knows who he is any more. At every stage in his life David Cameron has just drifted with the orthodoxy around him. The answer, for him, is always blowing in the wind.
So when people say he’s really right wing they’re almost right. He was really right wing once. He wrote the 2005 manifesto, after all. But then the wind changed direction so he turned with it. He loved free markets and Thatcher when all his friends did. He no doubt believed the same as Norman Lamont, when he worked for him.
He bears, as was said of Lord Derby, the imprint of the person who sat on him last. And we were the last people to sit on him. His team worked out that New Labour was popular. This was attractive to Cameron: looks like a new orthodoxy. Better join up.
This is the real charge against the Tory leader: that he has no settled convictions. He just has bits and pieces along the way. And you can’t lead if you are confused.

It is not just the attack on the Tories which is better. So, too, is his expression of a coherent vision for Labour, albeit one that borrows heavily from the well-thumbed manual Ideology-lite Pragmatism for Beginners:

The correct position on the use of the state is an agnostic one. If it helps solve a problem, it’s a good thing. If it doesn’t, it’s not. And there is no doubt that, in welfare, if you eschew use of the state for ideological reasons, you’ll find yourself in big trouble.
Without state action there would be less money spent on tax credits. That means there would be more children in poverty. There would be less money spent on pensioners, in the name of reducing means testing. So that would mean more pensioners in poverty.
It’s no wonder [the Tories] won’t sign up to our target to end child poverty. It would already be 1.7 million worse if we’d just continued their policies. It would be even worse if we adopted their policies now.
The point is that we are developing the right partnership between individuals and the state, not throwing all the responsibility onto one because we are committed to reducing the other.

There is much here which could be faulted, not least the very New Labour idea that ‘what matters is what works’: well, true, but it’s not a bad idea to think through if it might work in advance. And an even better idea to recognise that it’ll be more likely to work if it’s not controlled from Whitehall.

But, hey, I’m a Lib Dem. That I disagree with Mr Purnell is beside the point. At least I get his point. At least you can feel his speech has a narrative arc. At least it doesn’t read like it’s been stuck together with sellotape.

None of which means that Mr Purnell will, or is even likely to, succeed Mr Brown. But Labour should at least hire his speech-writer for their next leader.