“WHAT’S THAT, Daddy?” “It’s my mouse mat, Sam.” “Why is there a monster on it, Daddy, and a pair of curtains?” And so it was that I came to explain to my five-year-old son about Daddy’s role in the New Labour New Danger campaign of 1996. He listened attentively, but it’s fair to say that he is still absorbing some of the details.

Actually, so am I. In fact, after thinking about it for more than a decade, it was only on Monday evening, when I heard about the Government’s retreat on education reform, that I think I finally understood the whole thing.

You see, back in 1996 the Conservative Party was in a dilemma. Labour’s new leader, Tony Blair, was changing his party — abolishing Clause 4, saying nice things about Mrs Thatcher, ditching embarrassing policies. How, we wondered (I was working in Conservative Central Office), should we attack him?

Was Mr Blair just Bambi, an ineffectual figure, talking about “new” Labour but really heading an unchanged party? Or was he a thief, stealing “Tory clothes”? Or, perhaps, we should say that he had no views, that he was ready to “U-turn” on everything. Would that cut any ice?

Each of these approaches had drawbacks. Say that Labour hadn’t changed and you would look ridiculous; say that Labour was stealing Tory clothes and centre-right voters would be delighted, they could have Tory policies without having the Tories — perfect; say that he was making U-turns and voters would note with approval that he was switching from an unattractive policy to a more acceptable one.

Eventually we decided on an attack — we would argue that Labour was indeed new, but that its very newness was dangerous (though we weren’t entirely clear in what way).

“So Sam, we settled on this picture of a pair of potentially dangerous eyes, lurking backstage. Well no, darling, we didn’t win, exactly, but I got this mouse mat and, here, maybe you’d like to play with this New Labour New Danger badge. Press the button and, look, the eyes flash.”

We weren’t very disciplined even about our new line of attack. But if we had been, would it have worked? Certainly, John Major was never comfortable with it, preferring the “stole our clothes” attack. Meanwhile Labour’s gifted strategist, Philip Gould, thinks that even acknowledging the existence of new Labour was a terrible error. Is he right? How should we have resolved the dilemma?

I think that now, at last, I know the answer. But before I tell you what it is, let me explain why it matters.

In recent weeks Labour has shown precisely the same lack of discipline and confusion over how to respond to David Cameron that the Tories demonstrated over Mr Blair. Patricia Hewitt accuses him of U-turns. Jack Straw, in the course of a single interview, says that Mr Cameron is “not a new Tory” but that he was “abandoning policies to shift to our ground”, which the Foreign Secretary claims leaves voters wondering “do you have the imitation or the real thing? ”.

Gordon Brown does not think the Tory leader is U-turning enough, describing him as “Conservative to the core”. Meanwhile, the Prime Minister thinks Mr Cameron is U-turning too much. A couple of weeks ago Mr Blair read out a list of Tory policy changes at Prime Minister’s Questions until the Speaker cut him off. Mr Cameron’s advisers were disappointed with the Speaker, since they were delighted that Mr Blair was giving their policy changes free airtime.

My favourite attack, however, came from the Home Secretary. After months of reflection this political heavyweight and master of wit came up with: “Cameron basically understands nothing about nothing.” That one my five-year-old could absorb pretty quickly.

Now — here’s the answer to their problem, an answer that has taken me ten years to work out. The answer is that there is no answer. The problem is insoluble. But there’s a further point — you shouldn’t try to solve it.

In 1996 the Conservative Party should have realised that how Mr Blair was defined was not up to the Tories. It was up to Mr Blair. No one is going to trust a Tory to tell them what to think of a Labour politician. People would use Tory statements, even ones made about Labour, to help them judge the Tories. Our campaign failed not because it failed to “pin” Mr Blair but because, for various reasons, it made us look silly.

The right response to Labour’s new leader would have been to think carefully about the territory he wished to occupy and then try to deny him the political space to do so. This could only be done by shifting the Conservative Party. Every penny and every moment spent on the New Labour New Danger campaign should have been spent instead on remaking the image of the Tories.

This is the lesson for Labour, but it looks as if they are determined not to learn it. For on Monday, Tony Blair did something he almost never does — he made a disastrous political error. The only possible way to fight David Cameron is to ensure that he is forced to choose all the time between copying Labour and taking politically unpopular or unworkable positions. On public services, in particular, Labour must ensure that it champions any reform that is remotely feasible or popular, leaving the Tories advocating only unrealistic or unpopular policies just to distinguish themselves from the Government. For a decade Labour did just this. Now, with Ruth Kelly’s letter of retreat on education policy, it seems the will to do it has left them.

Just at the moment when it is most important for Labour to close down space for Mr Cameron, they are opening it up. They will rely instead on finding a consistent line of attack. And if they think that will work, then they know nothing about nothing.

daniel.finkelstein@thetimes.co.uk

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