In test cases of national importance, today's ruling at the Court of Appeal will decide whether "bedroom tax" regulations, introduced last April, are an "excessive and unfair burden" on people with disabilities, or a lawful and "integral aspect" of the Government's deficit reduction programme.
Backed by the Equality and Human Rights Commission, lawyers for five tenants are arguing that the regulations cannot be allowed to stand.
The Department for Work and Pensions rejects the "bedroom tax" tag and says the reality is a "spare room subsidy" has been removed from social sector tenants.
The change in regulations is expected to produce savings of £500 million a year, but opponents say they have had a "devastating" impact on many people and fail to reflect the actual needs of disabled people for extra space.
More top news
A Royal Marine from Northern Ireland who built explosives for an Irish republican paramilitary group had 43 hides, a court has heard.
A gay man has spoken of pain he suffered as a young boy when doctors gave him chemicals and electric shocks in attempt to 'cure' him.
Showers in the north tonight, elsewhere mostly dry.