But an analysis by the National Housing Federation, which represents housing associations, shows for the first time the true extent of the cuts faced by many families.
Based on cuts of up to 25% of a family’s housing benefit that the Government is considering introducing in 2013, a household deemed to be under-occupying a three-bedroom home in England faces losing up to £20.70 a week – or £1076 a year.
Such a household would be forced to choose between going into debt, struggling to meet payments by cutting back on essentials, or trying to move – even if no suitable alternative properties are available.
In London, a family under-occupying a three-bedroom home could have their housing benefit docked by an eye watering £1385 a year – the largest penalty of any region Britain.
And in the North West – the region with the highest level of under occupancy – families living in a three-bedroom property face a cut of up to £955 a year in their housing benefit.
Under the current system, social landlords allocate families a home based on an assessment of their needs. This may mean that teenagers are given their own bedroom and two bedrooms homes may be offered to young couples planning to start a family.
Where a family is out of work, housing benefit covers the rent, which is far lower than in the private rented sector. Under the new size criteria, a family may be penalised for "under-occupying" even where every bedroom in the home is in regular use. For example, benefit may be cut where teenagers have been given their own bedroom, rather than being forced to share.
Separated parents are set to be penalised for keeping a "spare" bedroom for when their children visit. And foster parents may receive a cut even where their bedrooms are occupied by foster children, who for benefit purposes do not count as part of the household.
Anyone deemed to be under-occupying by one bedroom stands to lose up to 15% of their housing benefit and those considered to have two or more "spare" bedrooms – even if they are in use – will lose up to 25% of their benefit. Two thirds of those affected are disabled, the Department for Work and Pensions has admitted.
Federation analysis, using figures produced by the Department for Communities and Local Government, show that the average social sector rent for three-bedroom properties in England is £83 a week. This means affected families face losing between £12 and £20 per week – or between £645 and £1076 a year.
The under-occupation penalty, part of the Welfare Reform Bill, will hit 670,000 working-age families across Great Britain when it comes into force in April 2013. That figure is forecast to rise to 760,000 by 2020 as the state pension credit age increases.
Ahead of the Bill’s Report Stage in the House of Lords, scheduled to begin on December 12, the National Housing Federation is calling on the Government to make the rules more flexible, to allow one additional bedroom above that permitted by the proposed criteria. Crossbench peer Lord Best plans to table an amendment to this effect but it will need the support of peers from across the political spectrum to stand a chance of making the statute books.
David Orr, chief executive of the Federation, said: "We have been deeply concerned about this bedroom tax for some time but these new figures show the damage will be far worse than previously thought.
"Thousands of hard-up families face penalties of up to £1400 a year simply because the Government have deemed their homes are suddenly too big for their needs.
"This will have disastrous implications for huge numbers of people already struggling to make ends meet in the tough economic climate, including foster carers, grandparents, disabled people and smaller families."
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