The right to buy your council house was one of Margaret Thatcher's flagship policies - and, undoubtedly, many people on low incomes who previously had no prospect of getting onto the property ladder are now home-owners. But critics voiced fears that it would seriously deplete council housing stocks and it would be the worst off who suffered. And now there's evidence that some of those fears may be coming to fruition, with the publication of a report by the London Housing Federation, warning of a "timebomb" for 2007.