This all seems reasonable enough. The idea that every patch of greenbelt land is a gem of exquisite beauty is a myth: much of it is dreary farmland, which has been doused in pesticides for years as farmers have squeezed the last penny out of the common agricultural policy.

Even so, it is comforting for the eco-toffs - none of whom has ever found it hard to raise the deposit for a mortgage, let alone been homeless - to imagine that resisting the pressure for more homes is a green issue. It isn't. It's a class issue. Britain is a small island with a tax system that encourages owner-occupation and a planning system that discourages it.

In those circumstances something has to give, and that is the growing number of families frozen out of the market. Rampant house-price inflation meant that in 2002 only 37% of new households could afford to buy, compared to 46% in the late 1980s, with almost 100,000 households now living in temporary accommodation.

The married couples forced to live with their parents and those in relationships who would prefer to be together, but are forced to live apart, are losers. The winners are owner-occupiers, who are becoming wealthier by the year as their homes grow in value; they have a vested interest in the status quo. Over time, increasing housing supply will reduce house-price inflation, so those sitting pretty will see their wealth increase more slowly.

Naturally, it would never do to admit that the real reason for opposing new development is essentially selfish, which is why the need to protect England's countryside provides such a convenient smokescreen. It's not on to suggest that the hoi polloi make the countryside untidy; far better to argue that this is about stopping developers' bulldozers from moving in to Malham Cove and Cat Bells.