Nobody could accuse the 84 per cent who want to preserve the green belt of being Nimbys - people who are all in favour of property development, but Not In My Back Yard. The green belts that surround so many of our cities are, by definition, in very few people's back yards, since so few are allowed to live in them. Quite a lot of those who want to preserve it must be young couples who are desperate to set up home together, whose troubles would be greatly eased if the Government or the local council were to allow the builders to venture further into the belt. Perhaps some of us - or even most of us - dream that one day we will own an idyllic house in the countryside. But the great majority of us realise that we never will. Our love of the green belt is a selfless love, motivated only by the desire to preserve something beautiful.

There are many, I know, who believe that we can have all the housing that we need, without encroaching at all on the green belt. They say that there is plenty of room for new buildings on brown-field sites in our inner cities. All we need do is to pack people in more densely, as the Deputy Prime Minister, John Prescott, has been doing for years. Build ugly new flats in places that are already ugly, so the thinking goes, and no harm is done. But the free-marketeer in me recoils from the idea. Why should people live in ugly places, stacked up in rabbit-hutches by government diktat, when almost all of us would prefer a bit of space to call our own?

God knows, I am better off than most Britons, living in a 4½-bedroom semi in the London suburbs. But there isn't a day that passes, when I am queueing for the bathroom behind my wife and four sons, when I don't wish that we had a little more room, and a garden more than 12ft wide. If I feel like that, how does my poor Polish cleaning-lady feel, sharing a single room in south London with her brother, her boyfriend and his brother? And what about all those tens of thousands of young people, as desperate to set up their own homes as their parents are to see the back of them?