We're not facing up to the real housing crisis

If we don't limit the growth in population in this country, then we cannot hope to limit the impact

Gordon Brown's announcement that the housing minister will now sit in the cabinet demonstrates that he sees addressing the severe shortage of homes as central to future government policy. This is seen as such an unambiguously good thing that anyone who expresses doubts about unrestricted house-building is obviously a nimby.

This was particularly illustrated by housing minister Yvette Cooper's cheap shots against "Tory reactionaries" in last week's New Statesman, and her demand that everyone "join the consensus for more homes".

But should we? Thanks to the latest "Strategic Housing Land Availability Assessment", for example, Oxford stands to lose 177 acres of green space in the coming 15 years. Golf courses, playing fields, allotments (my own included), green belt and the wonderful Warneford Meadow are all to be sacrificed on the altar of housebuilding.

Oxford is not alone - the accelerated destruction of green space for housing is a process that is underway right across the British Isles. Worst-affected is the overheated south-east of England, but Scotland, too, will suffer. The new SNP government in Edinburgh is to set up a task force to review planning laws in order to allow tens of thousands of extra homes to be built over the next decade. Green-belt land is being reviewed.

The impetus for this avalanche of bricks and mortar is coming not from anonymous market trends but by government diktat. In England, Westminster is demanding that regional assemblies deliver "spatial strategies", including vast quantitites of new housing, plans that are in turn imposed on local councils by these unelected and largely unknown bodies.

The government argues that vast numbers of new houses are needed in order to rein in house prices and make homes affordable for first-time buyers. But the truth is that construction of new social housing has collapsed in recent years - the vast majority of new building is at the high-price end of the market. Council planners reserve social housing as a political bargaining chip for controversial proposals - a stick to wield against "nimbies" who object to particularly destructive development on meadows and rare marshlands.

Moreover, strong evidence suggests that simply increasing the supply of housing will have little effect on overall house prices. As the Council for the Protection of Rural England points out, the United States, Australia and the Republic of Ireland have all seen strong house-price inflation, despite looser planning systems and higher rates of building.

Factors such as rising economic growth, relatively low interest rates and the surge in the buy-to-let and second-homes markets are also important in affecting demand, along with long- term trends such as decreasing household size, increased longevity and rising population.

Government policy on housing follows the predict-and-provide model that has failed for roads and airports, where increasing supply only stimulates yet more insatiable demand in a worsening cycle. England is already the fourth-most densely populated country in the world and the most built-up country in Europe. The south-east in particular is so overdeveloped that further economic growth can only destroy quality of life for those unlucky enough to live there. It is insane for councils to be forced to give up scarce allotment land to make way for executive housing at a time when we are being urged to grow more food locally. Commitments to biodiversity protection and recreational green space are worthless for as long as the Home Builders Federation continues to dictate government policy.

More controversial issues need to be put back on the agenda. By almost any measure, the UK - and England in particular - is seriously overpopulated. According to the Optimum Population Trust, our numbers are growing by more than 320,000 a year. Addressing this doesn't mean forced sterilisations or a Chinese-style, one-child policy, but it does mean giving incentives for people to have smaller families and addressing rising levels of immigration.

This last issue is understandably one which mainstream political parties - and environmentalists - are shy of addressing.

However, the logic is inescapable - if we don't limit the growth in population in this country, then we cannot hope to limit the impact of urban overcrowding and rural overdevelopment. As the old equation states: consumption multiplied by population equals impact. This is difficult political territory, but we need to enter it.