Some pensioners with spare rooms will be hit by reductions in housing benefit under what critics dub the Government's "bedroom tax", the Department of Work and Pensions confirmed.
Existing claimants in homes where someone of working age also lives have been spared the welfare cut, but new claimants under the Universal Credit scheme will face deductions.
Shadow work and pensions secretary Liam Byrne told the Sunday People, which uncovered the different status of new claimants, that the prime Minister needed to "get a grip".
Ministers promised to protect pensioners from the bedroom tax, but thousands are set to lose out.
David Cameron had better get a grip fast, before this scheme descends into total chaos.
A disabled woman and her partner have written to a minister urging a rethink on plans to cut benefits for tenants deemed to have spare rooms
The benefit cut for social housing tenants will put 'unbearable' pressure on families with a disabled child.
Bedrooms in some foster homes will be classified as vacant, but the government insists funding for foster carers will be protected.