Almost 60% of households affected by the "bedroom tax" changes were in arrears as a result of the cut to their housing benefit, an internal Government review has found.
Under the policy, social tenants deemed to have a spare room see their rent eligible for housing benefit reduced by 14%, rising to 25% if they have two or more extra bedrooms.
Some 20% of those affected had paid none of the shortfall and 39% had only paid their landlords part of the money owed, the interim report for the Department for Work and Pensions (DWP) found.
The report found 522,905 households were affected by the policy in August 2013, which equates to 11.1% of social tenancies. Some 57% of claimants were cutting back on household essentials and 35% on non-essentials in order to pay their shortfall.