Changes to the "homelessness duty" will mean councils can offer people private sector accommodation instead of being obliged to offer social housing.

BBC: At-a-glance: Localism Bill

Mr Forbes claimed the changes would not make the predicted savings because "the logical economic choice for a tenant who's getting the bedroom tax imposed on them is to move to more expensive, smaller private sector accommodation".

BBC: MPs debate impact of 'bedroom tax' changes in Wales

Mr Blackwood said the legislation would marginalise those on low incomes who will find it hard to get accommodation in the private rental sector.

BBC: Fears private rents could rise by up to ?25 a month

Private prisons have held a higher percentage of their prisoners in overcrowded accommodation than public sector ones every year for the 13 years to 2010-11, it said.

BBC: Most prisons are overcrowded - Prison Reform Trust