My wife playfully divides newspaper columns into two sorts — those that are obvious, and those that are rubbish. As I left for work this morning I promised her one that was obvious. And, so help me, that is what I will deliver.

You see, I intend to put forward a truly plonking point. The only thing to be said in its favour is that it is right, important and not one you hear that often. And that, my friends, will have to do.

My prosaic point concerns smaller government. Despite 30 years of concerted effort, the Right hasn't got very far arguing for smaller government. Well, it occurs to me that perhaps the Right hasn't been making the best case. Two confusions hold back the case. The first is the confusion between the United Kingdom and the United States. It is this confusion that provides the solution to an otherwise baffling mystery — why do so many on the Right believe that simply calling for smaller government would be politically attractive?

Appeals to the idea of freedom are very powerful in the US. People drive around with the words “live free or die” on their number plate. Abstract appeals to liberty can help to defeat measures to curb gun use — live free and die. Limiting the size of government is tied up with the very identity of the country.

Repeat the same rhetoric in this country and you don't get very far. We believe in liberty, of course we do. We think of ourselves as a proud and free people. But we are a practical people, too. A “live free or die” number plate would be seen as, basically, a little bit silly. Talk of smaller government is seen as a businesslike suggestion rather than an appeal to the hallowed teaching of our ancestors.

The second confusion is between smaller government and cutting taxes. Reducing the tax bill is one practical advantage of smaller government that the Right is willing to talk about. The problem is that cutting tax and cutting the size of government are not the same thing. There are plenty of ways of cutting government — school vouchers, for instance — that might increase tax.

The result of this confusion is that when talk of smaller government is not airy rhetoric, it is reduced to penny-pinching. The argument is made for good housekeeping, for cutting out “waste”, for doing the same things but more cheaply. There is merit in this but voters are, understandably, pretty sceptical.

So what is my alternative case for smaller government? It is this — there aren't enough hours in the day to run big government properly.

When those discs went missing, Alistair Darling's supporters said that he couldn't reasonably be held responsible for the act of a junior official in a distant office. The scary thing is, they were right. In fact, even when the mistakes turned out to be ones made at a more senior level, the feeling persisted that it wasn't fair to blame it on the Chancellor.

We all intuit that Government is much too big and ministers much too busy to really be expected to, er, run the tax collection system. All I am suggesting is that conservatives turn that intuition into a powerful understanding of the problems of big government.

The head of Tony Blair's delivery unit, Sir Michael Barber, has recently published his account of his time in No 10. Instruction to Deliver is a very good book, an extremely illuminating volume. Sir Michael explains that he was only able to make progress on delivering better public services by excluding from consideration the vast majority of what the Government was doing. By focusing on four departments and just ten targets, his unit was able to make an impact.

Even then, he struggled to find time in the Prime Minister's diary to review progress on these targets — just an hour for an entire department every three months. Sometimes, when the moment came, Mr Blair was too busy to attend. He was off fighting a war, or meeting the Chinese Prime Minister, or negotiating a new European constitution, or whatever. On other occasions he was too tired to pay proper attention or read the documents. Sir Michael reports that often his briefing to Mr Blair had to be restricted to whatever he was able to say while the two were walking down the corridor to the Cabinet Room. And remember — this expenditure of time represented an improvement on the first term.

Mr Blair was not unique. My experience of meetings with John Major and senior ministers to consider his programme of legislation was of a constant stream of notes being passed into the Cabinet Room, requiring decisions while the discussion continued.

When Sir Michael was persuaded, against his better judgment, to extend the coverage of his unit to all departments, he quickly found it unsatisfactory. The conclusion of his book is unmistakable — the individuals at the top of government haven't the time to do all the things they are trying to do.

Take the nonsense at the Security Industry Authority, merrily giving out licences to illegal immigrants to guard the Prime Minister. This body was set up in 2003 to regulate nightclub bouncers. Fair enough. It's not as if this idea was entirely stupid. It's just that what with running every school and hospital in the country, fighting a war in Iraq and preparing for the Olympic Games, it's hard to see a Nightclub Bouncers Authority getting enough attention to be run properly. And the rest is history.

This is not an argument that will excite philosophers or make a good bumper sticker. But it might make sense to the practical British voter. Government ministers shouldn't have a reach greater than their grasp. They shouldn't seek to do more than they have hours in the day to do properly. That's my case. Plinkety plonk.

daniel.finkelstein@thetimes.co.uk

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