I’ve caught myself twice this week saying something that on reflection I don’t believe. First was to an interviewer on BBC News 24 after Gordon Brown’s drubbing at Prime Minister’s Questions on Wednesday. My argument rolled from the tongue with dignified fluency so, pleased at the sound of it, I trotted it out again the following day over pudding with the Hastings & Rye Conservative Association, where the mellow mood induced by a succulent luncheon seemed conducive to the civilised drift of my case. Hastings is a thoughtful place, and there were murmurs of grown-up approval. How true, how very true.

Except that I don’t think it is true. Actually (said an inner voice) you believe the opposite. You should say so, even if it sounds more shrill than wise. There is wisdom enough on The Times.

Here was the wise argument: “David Cameron and his Conservative colleagues were entitled to their half-hour of fun at Prime Minister’s Questions, at Brown’s expense. They landed their punches. But they should not think this will serve as opposition policy for the next two years. ‘Hah-nah-nah’ does not add up to a manifesto, and the British electorate dislike knockabout.

“After a deserved week of crowing, the Tories should now return to fleshing out their own policy platform. Britain wants to hear a mature and constructive alternative to new Labour, put calmly and without personal abuse. Criticise Labour policy by all means; but criticise measures, not men.” Sage advice. And wrong. This Government is bereft of measures to criticise. Its centre is hollow. New Labour is not and never was “measures”: it is a marketing exercise; it is men or it is nothing. So go for the men, I say. Kick the living daylights out of them. Humiliate them. Knock them all over the shop. Puncture their fragile confidence.

Bring them down.

As for Tory measures, beyond a few eye-catchers like abolishing death duties, who’s interested in the contents of an opposition party’s likely manifesto in two or three years’ time? Behind the scenes, of course, work must go on at a furious pace and in a deeply serious way; because the Conservatives must be ready soon for government. From this work the occasional early plum may emerge fit for production at the dispatch box. Good. Produce it. Let people know there’s more where that came from. But don’t make policy-wonking the centrepiece of these next two years.

So pull no punches. Pile in, fists flailing. The centrepiece of the Tory platform must be, not an intriguing new scheme for tax-benefit taper, but the fact that Gordon Brown is a great big booby: a hollow man surrounded by a bunch of secret doubters, tired has-beens and timeserving second-raters. Rumble him. Rumble them. Jump up and down on their heads and make their inadequacy famous.

This is not a philosophy recommended for all political opposition in all circumstances; it is a recommendation for this Opposition in these circumstances. The circumstances are particular. New Labour is an empty vessel. The governing party is a political movement without content.It’s all a bluff. It always was. Third-way politics will not be unpicked, it will implode. Gordon Brown will not be countered, he will be debagged. The deserved fate of this administration is infamy. The way to bring it about is mockery, exposure and abuse.

What, until recently, has been holding the Cameron Conservatives back? It is, I believe, their overestimate of the whole new Labour project. Triggered by the successes of Bill Clinton in US politics, a tremendous amount of balderdash has been spoken and written in Britain about “triangulation” – as though because the word was novel and contained five syllables it pointed to a brilliant new strategy, only recently discovered, in America.

Ever since I studied political science at Yale as a postgraduate, I have harboured a deepening suspicion of the American intelligentsia’s Teutonic passion for grand theories with whizz-bang names and a propensity rapidly to take leave of the common sense in which they may once have been rooted. If the theory of triangulation had been published first in German we should have met it with scepticism; but it had the good fortune to be born in America, where they think in German but speak in English, and became one of those words that, uttered by the wise, are repeated by the right-on without anyone asking its precise meaning.

I think it means shifting your position towards – if not all the way to – the most popular position available. Expressed thus it loses its mystery, and can be seen as a banal offshoot of Aristotelian ethics (the theory that the “right” thing to do lies midway between going too far and not going far enough). Both are susceptible to a fatal criticism: taking their bearings from prevailing opinion, they do not ask whether prevailing opinion might simply be wrong or require alteration by the force of argument.

Because Tony Blair was such a charmer, and his arrival coincided with a sustained economic recovery and a very deep public yearning for an end to Tory government, he impressed a generation (including a Tory generation) with an apparent ability to walk on water. He told people this was because he had found the Third Way, and they believed him. Some Cameroons started looking for it too.

But now Mr Blair and his magic have gone, the leaves are turning brown and the wind chillier, and the chief economic wizard who has succeeded him appears a shrivelled figure as the curtains are pulled back. We begin to ask ourselves what he and his former master actually did in the decade they ruled together. The answer is that Blair did nothing, and Mr Brown did well enough while he stuck to Tory spending plans, and then began to drift: how badly, we are only now beginning to understand. Few of their Cabinet colleagues are remembered at all.

But we fell for it. We were suckered into what was little more than a personality cult, and now the personality has departed, leaving a hefty bill, deteriorating finances, no new ideas, and Mr Brown.

Norman Tebbit once told me that, when learning marksmanship, he found his eye and reflexes laggardly until his instructor replaced the instruction “Shoot!” with the instruction “Kill!”. Then all at once, said Lord Tebbit, eye and brain locked into deadly synchronicity. Likewise for the opposition front bench. After the effective disintegration this week of command and authority at the very top of the Government, I have a new Latin motto for the Tory crest. “ Ad Hominem, Ad Hoc, Ad Nauseam.” Or, in Norman’s terms, kill.

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