One doesn't often learn much about political strategy and health care reform from a horse. But if David Cameron does not know the story of Norton’s Coin, he may find it useful.

The horse, trained by an obscure Welsh hill farmer, was entered for the blue riband of horse racing, the Cheltenham Gold Cup, in 1990. Up against the best steeplechasers in the country, not least the odds-on “people’s favourite”, Desert Orchid, Norton’s Coin was “more a candidate for last than first”, as the race card put it on the day. Norton’s Coin’s odds were 100-1. No serious observer expected him even to be placed.

You know what I am about to write: Norton’s Coin won. The received wisdom was wrong.

The received political wisdom is that the Conservative Party’s supposed hostility to the NHS is its Achilles’ heel and the sooner it is neutralised as an issue by Mr Cameron, the better. Thus his speech yesterday, in which he expanded on his weekend advertisement, which stated that: “We believe in the principles and values of our NHS.”

Until yesterday, the Conservative leader had not put a foot wrong. His broad strategy of moving the party — and, crucially, its appearance — to the centre is the only sensible option. Whatever one thinks of Tony Blair, his strategic genius is indisputable. Labour has won three elections in a row because Mr Blair has taken hold of the centre and pushed the Conservatives away from it. It is easy to sneer at the involvement of Bob Geldof and Zak Goldsmith but no party has ever won in Britain without being seen as centrist. Until Conservatives no longer seem in the eyes of the chattering classes like emissaries from Planet Zarg, the party will forever be doomed.

But that raises a fundamental question: where does the centre lie? The centre ground in the 1950s — Butskellism — was very different from the centre in the 1980s, defined by Thatcherism. It moves as circumstances and voters’ views move.

Clearly, from the 1950s, when a cross-party acceptance of the NHS emerged, the NHS was bang in the middle of the political centre. Even the Conservatives’ attempts at limited reforms in the late 1980s and 1990s — the internal market — were regarded by many otherwise sensible people as a form of ideological extremism. So it is understandable why the otherwise sensible Mr Cameron is keen to establish that the NHS is, as Margaret Thatcher felt the need to put it, “safe in our hands”.

But the centre is moving. Attitudes are changing. For decades, the alibi for the NHS’s failings was its supposed underfunding. Now spending is greater even than the sums demanded by those who argued that underfunding was to blame.

The result? The Office for National Statistics found in 2004 that productivity had fallen by about 1 per cent per year since 1997. And both the Prime Minister’s Strategy Unit and the Organisation for Economic Co-operation and Development went further, measuring falling productivity of up to 20 per cent since 1997.

David Cameron’s response to the disappearance of billions of pounds into the NHS black hole is to argue for improved management and more fiddling with structures, but to run a mile from questioning the system itself. The Conservative solution is: we’d do it better than they would.

But he is walking away from real reform at the moment when its need is at last becoming understood by voters. In a poll for the think tank Reform in February 2004, 69 per cent agreed that: “The NHS was the right idea when it was introduced in the 1940s, but Britain has changed and we need a different healthcare system now.” Only 40 per cent agreed that: “The Government is right to rule out alternatives to the taxpayer-funded NHS.”

In nailing his colours so firmly to an exclusively tax-funded NHS mast, Mr Cameron is making a huge mistake, both politically and for the good of the country. Labour’s policy of spending as much money as possible and fiddling with the system is a form of controlled experiment to discover if that is indeed all that is needed. The answer is now becoming clear: it isn’t.

For years, those of us who have argued that it is the very notion of an entirely tax-funded system that is the real problem were dismissed as ideologues and lunatics. Now, with the evidence showing that the NHS cannot deliver even with massive funding, real reform has at last entered the realms of acceptable debate.

That is a huge transformation in the political landscape. Yet just at this moment, Mr Cameron has chosen to cut off all such talk, neutering his attacks on Labour with his “me too” policy, and destroying any prospect of the reforms that might actually give us a system to deliver the best healthcare.

His speech included a litany of what the NHS does not provide. Indeed. But where does he think the money is coming from to pay for the extras? Even Gordon Brown’s massive cash injection — which is anyway about to come to an end — isn’t enough to cope with today’s demands and, as Mr Cameron rightly pointed out, they will be even greater in the future. How much more than Labour is he proposing to tax us to pay for it all?

We have to move to a mixed economy of healthcare funding. On the one hand Mr Cameron complains that we are so far behind the continent and, on the other, he explicitly rules out — indeed, condemns as unBritish — those very mechanisms that have made their resources possible.

Instead of betting the Conservative Party’s political fortunes on Desert Orchid — the NHS — he should notice the widely dismissed 100-1 outsider accelerating up on the rails.