Martin Westgate QC, appearing for the 10 test cases, told two judges the regulations were flawed as they failed to deal with the needs of the disabled and the amount of space and the number of rooms they realistically needed if they were not to suffer discrimination because of their disabilities.
Each of the claimants has a need, because of disability, to occupy accommodation larger than that which would be allowed to them under the size criteria.
The key point is that benefit must match need for accommodation size where that need has been identified.
In a three-day hearing, he is asking the court to rule that the new regulations breach Article 14 of the European Convention on Human Rights, which protects against discrimination.
He also argues that the Work and Pensions Secretary, has failed to comply with his public equality duty under the 2010 Equality Act and the discriminatory element in the regulations must be quashed.
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A milder night ahead with patchy rain in the south giving a soggy and slow start to Saturday in places.