Since becoming leader of the Conservative party, David Cameron seems to have stopped believing in Conservatism - or that's what he'd like us all to believe. Because David Cameron wants to win an election, and he has seen what has happened to those who have tried to make a case for conservative government; they've lost. Despite campaigning for his party's leadership promising to update conservatism for the modern era, he has since abandoned a whole stream of long-held conservative views for what he describes as "liberal" positions. Comparisons with Tony Blair's leadership of the Labour party are almost too obvious to be worth making.

He has gone further, reaching out to Liberal Democrats, appealing for defectors. Today, he finally got one. Not a big fish, but credit where credit's due - Cameron is a man of considerable political talent and he has succeeded in creating a climate where the Tories are seen as a potential future government. A cynic might put that differently: that they're now a party where those who put ambition before principle can find a home. Not since the heady days of the early 80s has anyone thought that joining the Tories was the path to a successful political career.

If this is to be anything more than a minor diversion, a clever but ultimately pointless stunt, Cameron's claims to be a liberal must be submitted to scrutiny. Furthermore, the question is not only whether Cameron himself is a liberal, but whether his party can itself be called 'liberal'. On closer inspection, much of Cameron's 'liberal' rhetoric has little relation to liberalism itself. He talks about keeping current tax rates, about investing in public services. He talks vaguely about 'inclusion'. The new virtue of Tory politics is apparently 'stability'. Liberals are, by nature, reformers. To Liberals, 'stability' sounds like an excuse for continuity, an excuse for the status quo. Change is needed, but Cameron seems to offer little except a changing in of a greying Tony Blair for a younger model. His only unique idea is the resoundingly illiberal plan for compulsory community service for school-leavers.

The history of conservative liberalism (or liberal conservatism?) is, however, a long one. There is not space here to rehash the entire history; suffice to say that, at the beginning of the 20th century, Liberalism and Conservatism were the dominant political forces in Britain. Liberalism stood for reform, Conservatism was instinctively opposed to radical change. This was the height of British power and influence in the world, with Britain having a powerful economy which had been opened to free trade thanks to the efforts of Liberal governments in the 19th century. However, this was also the beginning of the age of socialism. The First-Past-The-Post electoral system meant that there was not room for two reforming parties, so the rise of the Labour party led to the eclipse of the Liberals. Many Liberals, fearful that Labour would erase their achievements, joined forces with the Conservatives in an effort to preserve the Liberal heritage.

This mixing of the political gene pool went on for most of the 20th century. Those who saw a threat in an all-powerful state had little choice but to either vote Labour and hope for the best, or vote Conservative out of a desire to put the brakes on. It is also worth remembering that, at the time, those states furthest in the development of socialism included the Soviet Union and Mao's China. Opposition to authoritarianism was not a simple matter of arguing over moderately high taxes, it was motivated by a fear of an eventual total loss of freedom.

To this day, there are genuine liberal beliefs held by some conservatives. There are those who understand liberal values and have endured a marriage of convenience with genuine conservatives as a means of getting those views into government. The FPTP voting system rewards such behaviour. It is also worth pointing out that Britain - perhaps England in particular - has a strong liberal heritage, and insofar as conservatives reflect the traditional values of the country, they have reflected this liberal strain.

But conservatives are not liberals, they are conservatives. This distinction has been drawn best by the late Nobel Laureate, Friedrich August von Hayek in his essay "Why I am not a conservative". Writing in 1960, near the low point of the liberal eclipse, he begins by writing that " At a time when most movements that are thought to be progressive advocate further encroachments on individual liberty, those who cherish freedom are likely to expend their energies in opposition". Hayek makes clear that any alliance of liberals and conservatives is one of expediency, rather than fundamental compatibility of their basic principles. Only because the alternative is authoritarian is it justified for liberals to support conservatism.

Hayek goes further: "Let me now state what seems to me the decisive objection to any conservatism which deserves to be called such. It is that by its very nature it cannot offer an alternative to the direction in which we are moving. It may succeed by its resistance to current tendencies in slowing down undesirable developments, but, since it does not indicate another direction, it cannot prevent their continuance. It has, for this reason, invariably been the fate of conservatism to be dragged along a path not of its own choosing.". Following Cameron's wholesale acceptance of the terms of the New Labour project, these words seem almost prophetic.

Of course, Cameron is not the first to claim to have re-made the Conservative party in a liberal image. Many around Margaret Thatcher in the 1980s were fond of the label "neo-liberal" and believed that, in reversing elements of socialism, they were serving a liberal purpose. And, again, to give credit where it is due, it has to be admitted that some of Thatcher's reforms did just that. But many of her reforms did nothing to advance a liberal agenda. Whilst some of her economics were liberal (can anyone seriously sustain an argument against privatising British Telecom now?) she showed little insight into the fundamental principles that lay behind. Liberalism is about dispersing power, ensuring individual liberty and democratic accountability of government. But Thatcher presided over a considerable centralisation of power at Whitehall, and the creation of a vast number of unaccountable quangos.

In many ways, Thatcher was simply an "anti-socialist", rather than a liberal. In some cases, her opposition of socialism led to liberal outcomes - the privatisation of needlessly-nationalised industries, for example, or moves towards free trade. But in other cases, her anti-socialism was illiberal; she strengthened the grip of national government over local councils, reducing local control and local accountability. The national curriculum was an effort to wrest control of education away from socialist councils, but it resulted in a massive centralisation of the education system. She failed to see that a diverse, decentralised government is essential to a liberal society. She believed that a monopoly on power - something liberals oppose on principle - was acceptable if it was under the control of a Tory government. Insightful Tories may reflect on this when they lament Labour's centralisation, or their micro-managing education policies.

It is sometimes claimed, by those on the Labour left, that Tony Blair is a Thatcherite - this being one of the Labour left's most stinging insults. But in reality, he's another politician in a long-line of Labour-Conservative consensus. The foundations of Attlee's nationalisations were laid by Churchill's war government, "Butskellism" followed and as late as the 1970s Ted Heath's government was described as doing "the spade work of socialism" by no less than Tony Benn. The drift towards centralisation and authoritarianism carried the Conservatives with it. If Thatcher was an aberration, Blair is the restoration of this tradition. And now, following in that line, is David Cameron.

Placing himself in the mainstream of the governing philosophy of the last 60 years could be described as a smart move, were it not such an obvious solution to the Conservative party's problems. As an electoral strategy - offering a milder version of whatever the Labour party is offering - it has been proven to work by a succession of Conservative governments throughout the 20th century. But whether it's the right thing to do is open to question - and only a very brave liar could describe it as the liberal thing to do.

Those who want to see a genuine liberal voice in British politics cannot, in my opinion, look to the conservatives to provide it. Conservatives already have an ideology - conservatism - and one can no more espouse two ideologies at once than one can ride two horses at once. I remain open to the possibility that perhaps I am wrong and Cameron might be telling the truth about his 'liberalism'. But to prove it, he would have to be willing to exorcise his own party of those who see themselves as conservatives and not as liberals. The day he does that is the day I will believe that David Cameron is offering a liberal party for election.

Liberals must understand that only a liberal party can offer the kind of reforms they want. Only a liberal party can change the terms of the debate, can entrench liberal principles and can build a lasting consensus around liberal values. The tug-of-war between Labour and Conservative can only yield Labour-lite and Conservative-lite, positions drawn from points along the line between left and right. Only liberals can break the left-right divide and achieve the radical decentralisation and dispersal of power, the reform of public services and the restoration of civil liberties that is needed.

The final word on this matter, I think, should go to Hayek:

But, though there is a need for a "brake on the vehicle of progress," I personally cannot be content with simply helping to apply the brake. What the liberal must ask, first of all, is not how fast or how far we should move, but where we should move. In fact, he differs much more from the collectivist radical of today than does the conservative. While the last generally holds merely a mild and moderate version of the prejudices of his time, the liberal today must more positively oppose some of the basic conceptions which most conservatives share with the socialists.