IF THE Conservative Party didn’t exist, would we need to invent it? Certainly not all its MPs seem to think so. Only a few days ago, one prominent Cameron-supporting MP told me that “you don’t really need us as long as Blair is in power”. Apart from raising the obvious question of what exactly had propelled this person up the political ladder in the first place, this fails to grasp what, I think, David Cameron is really about.

Some Tory strategists believe that the electorate wants more Blair, but a Blair detached from his rebel backbenchers. They hope to tarnish Gordon Brown by presenting him as the “roadblock” to Tony Blair’s reforms and as a tax-and-spend socialist. That will not be easy: the Chancellor has seen them coming. He will soon be donning the ragged mantle of Prudence anyway; his own spending plans assume an end to the splurge by 2008. But trying to split Mr Brown from Mr Blair misses the point. What many of us want is not more Blair, but less government. For all their differences, Mr Brown and Mr Blair share an authoritarian, interventionist instinct. And it is that — not the minutiae of who believes what on public service reform, a subject that so fascinates the media — which most worries many of us.

Few of us would want to live in a country where everything that is not forbidden is compulsory. But we seem to be heading that way. There have been so many criminal justice, disability and equal opportunities bills that an entire industry has grown up to train lawyers to keep up with the new laws. The Animal Welfare Bill will police our pets. The Racial and Religious Hatred Bill will put a policeman in our head to stop us criticising religion or superstition. There are 200 terrorist offences on the statute book but we are told that we must abolish trial by jury and strain the suspension of habeas corpus to breaking point by extending the detention of terror suspects without trial. This Government measures its progress by the amount of legislation, irrespective of the consequences, even when half is counterproductive and a quarter has to be rewritten.

The unelected toffs, the pensioned-off do-gooders and thinkers in the House of Lords, have become the last bastion of our civil liberties. Thank heaven for them. But we know their days are numbered.

Even the most well-meaning interventions can be divisive. It is not wrong to want people to be thinner, healthier, better and more equal, but if the State is used as a weapon to force people to conform, the glue that holds us together as a nation will eventually lose its stick. Half the nation will be jostling for state subsidy, the other rampaging in lawlessness outside. The Government that once had a communitarian belief in give-and-take, in rights and responsibilities, seems to have lost its sense of proportion.

Mr Cameron instinctively seems to understand these concerns. His remark on Tuesday that “there is such a thing as society; it’s just not the same thing as the State”, was a nod to where the new faultline will be in British politics. Tony Blair’s Third Way has delivered an awful lot of State. Even his latest education White Paper, a genuine effort to move in the opposite direction, will leave many bureaucratic obstacles in place to stop schools from deciding what to teach, who to hire and on what terms. When Mr Cameron offers to support the Prime Minister on reforms that genuinely make schools freer, he is using his power to help to move things in the right direction — which is what politics should be about. But there will not be many such areas of agreement, because in the end even the Prime Minister finds it hard to let go.

The challenge for the Tories is to articulate a third way that marries social action with free-market economics, but does not just assume that the flowers of civil society will spring up automatically if the State retreats. It was no accident that Mr Cameron chose to mark his first day as Tory leader yesterday by announcing his social justice commission at an East London charity. A fierce Labour-Tory battle is brewing over the voluntary sector, which Cameron ’s Conservatives see as a much more effective way of tackling family breakdown, drugs and other social problems than the dead hand of the State. Labour will (rightly) claim that it got there long ago, and that many charities are already involved in public service delivery. On Monday Mr Brown moved pre-emptively to shore up his plans for a national youth community service, an idea that Mr Cameron has also been enthusiastically touting. Mr Cameron’s Conservatives allege that Mr Brown’s service would be run from the Treasury; theirs by the voluntary sector. They rightly believe that charities have been constrained by box-ticking bureaucrats, that the voluntary sector deserves a level playing field when bidding for government contracts and they are too often overlooked or cold-shouldered by public agencies. The political space that waits to be colonised is one that combines social justice with free-market economics and civil liberties. The “Orange Book” Liberal Democrats are moving there, but they have yet to convince the rest of their party to embrace the free-market bit. Mr Cameron’s talk of marrying economic liberalism and economic empowerment, of the limitations of the state but the need to “mend society” stakes a clear claim to that territory.

Do not assume that Mr Cameron is “wet” on economics because he is socially liberal — George Osborne, his Shadow Chancellor, has thought his way through flat taxes, after all. Do not assume that he doesn’t understand the voluntary sector — his campaign manager, Steve Hilton, has spent years working in the field of social action. And do not assume that his opposition to 90-day detention of terror suspects was a one-off piece of opportunism. We may yet see a party emerge in the true tradition of Tory liberalism, nurturing both civil society and civil liberties. If that is what David Cameron is trying to reinvent, all power to him.

Times Recommends

• We have kit and leadership. Let’s go
• Behind the scenes at the biggest deal
• Conferences — what a waste of money