Without an increase in social housing London and Londoners will suffer

I went to London's richest borough a while ago to meet some of its poorest people. There were four of them: a woman, her two adolescent sons and her little daughter. They were living in a two-bedroom social housing flat several floors up. The boys shared one bedroom, the girl shared with her mum. The woman's husband, the father of her children, had been removed by force of law due to his violent misconduct in the home. The daughter had speech and learning problems (though she drew me a lovely picture while I was there). The mother worked part-time. She and her family had lived in the flat since her eldest child was a baby and had been seeking somewhere larger for four years. What options did she have? Not many. The borough's waiting list was a stone wall and renting privately was out of the question – the average price for a two-bed place in their borough, Kensington and Chelsea, was recently judged the highest in the country at £2,714 per month. The woman told me that she'd been offered larger accommodation with a private landlord, but it was a one-hour journey away. What about her job, her children's schools, the friends who help her out, the social care professionals she'd got to know? Staying put was hard. Leaving would have made life harder still. Her predicament was but one among multitudes of examples of London's deepening housing calamity. More than 360,000 of its households – about one-tenth of them — are on borough housing waiting lists, nearly double the number at the start of the century. Private rents swallow more than half of incomes in most parts of the metropolis . Sensible mortgage deposits are miles out of reach for most first-time buyers. The most cautious measure of overcrowding, which is just one part of the madness, finds that 200,000 London households with children don't have sufficient space . This strains family life, fuels ill-health and sabotages children's futures: it costs individuals and society fortunes. Yet a global megacity containing brownfield sites, which, in the words of its Conservative mayor, "have the potential to provide around 250,000 homes," is unable to supply just one extra bedroom for a struggling example of its working poor without relocating her and her kids to what might as well be the middle of nowhere. The government's solution is, of course, to make things worse, although perhaps we should be grateful for small mercies. Labour housing expert Tony Clements notes that the fiercest attacks on its new housing strategy have come from laissez-faire ultras horrified at the use of any public money to stimulate house building of any kind. Their preference is to further liberate the very market forces that have caused rents and property prices in the metropolis to soar. Meanwhile, the coalition has slashed grants to housing associations and confected a new "affordable rent" product designed to generate homes that will be too expensive for families such as the one I met in Kensington and Chelsea without the help of housing benefit. That's the welfare payment, you may recall, that George Osborne is determined to reduce, especially in London where private sector rent inflation — 12% in the last 12 months – hits the taxpayer to the loony tune of half a billion quid a year, more than double anywhere else in Britain . Greater supply is, of course, the answer, but it needs to match need. Yet the supply of genuinely affordable homes in London is drying up, as it is everywhere else. Boris Johnson makes large claims for his record in this field, but he's been spending cash coughed up by Gordon Brown – cash that has now run out. Logic points to the public financing of homes that low and middle-income Londoners can afford to rent long-term rather than forcing them to use private landlords, but this approach collides with ideology – it is a Tory principle that social housing is a social ill . What will happen to London households with no, low or middle incomes feeling the capital's ruinous housing cost crunch? The housing benefit squeeze, which will start in earnest in January, will hammer the very poorest, forcing thousands to pack their bags and move somewhere smaller or poorer – even Mayor Johnson agrees. Or maybe they'll just eat less food instead. London's private landlords anticipate buoyant demand, and rents floating on upwards accordingly. The bottom of the housing ladder will remain hoisted from the reach of most Londoners of modest or even average means. The government strategy, still living the fading home ownership dream, proposes underwriting mortgages of first-time buyers of new homes, yet everyone seems to agree that Laying The Foundations is a recipe for sub prime catastrophe. Where does all this leave our Royal Borough of Kensington and Chelsea family? Stuck with what they've got, it seems – and with very little hope for the future.