In a sign that ministers are increasingly losing the argument over the bedroom tax, Iain Duncan Smith has announced  that 5,000 foster carers and some armed forces families will be exempt from the measure, which will see housing benefit reduced by 14 per cent for those deemed to have one spare room and by 25 per cent for those with two or more, an average loss of £14 a week or £728 a year.
Those tenants who have children serving in the military will no longer be charged for the vacant room while they are away. In addition, carers will be allowed extra space as long as they have fostered a child or become a registered carer in the past 12 months. Yesterday it was announced that families with severely disabled children would be exempt.
It would be churlish not to welcome these concessions, but the overwhelming majority of the 670,000 tenants due to be affected will still lose out, including thousands of disabled families. In his written statement , Duncan Smith emphasised that Discretionary Housing Payments would remain available for "other priority groups" including those "whose homes have had significant disability adaptations and those with longterm medical conditions that create difficulties in sharing a bedroom."
But research published by the National Housing Federation shows how inadequate this support is. Were the £30m discretionary fund to be distributed equally among every claimant of Disability Living Allowance affected (229,803 in total), they would each receive just £2.51 per week, compared to the average weekly loss in housing benefit of £14.
Having conceded that those families with severely disabled children should be exempt, on what grounds does the government maintain that those with one more or disabled adults should not? In a recent letter  to George Osborne calling for all disabled families to be spared from the cut, the heads of seven charities, including Carers UK, Mencap and Macmillan Cancer support, cited one typical case.
Jean and Carl live in a two bedroom house. Carl has suffered from serious health complications for years and is now unable to work as a result of a series of operations and treatment. Jean juggles caring for her husband with a job at a local supermarket. They are unable to share a room because Carl’s condition causes very disrupted sleep and if they share Jean cannot sleep. Her shifts at work mean she frequently has to be up at 4am and she would simply be unable to do this if she could not get a good night’s sleep. They fear they will not be able to make up the shortfall in their Housing Benefit and if forced to downsize Jean is worried about her ability to do her job if she is unable to sleep properly (names changed to preserve anonymity).
With increases in most working-age benefits capped at just 1 per cent and a shortage of one bedroom houses for tenants to downsize to (there are 180,000 English social tenants "under-occupying" two-bedroom houses but fewer than 70,000 one-bedroom social houses available), the bedroom tax is both immoral and unworkable. Labour's Helen Goodman has written movingly on The Staggers of her experience of living on £18 a week , the amount many of her constituents will be left with after the measure is introduced. The only "concession" we should accept is the full abandonment of the policy. But, at the very least, ministers must protect the disabled, who, more than any other group, will suffer the most from this cut.