Iain Duncan Smith has been given two weeks to demonstrate why the bedroom tax should not be subject to a judicial review.

The work and pensions secretary is facing a legal challenge against the government's 'under-occupancy' charge by law firm Hopkin Murray Beskine on behalf of 10 disabled children.

The ten vulnerable claimants - among a total of 22, including seven parents and five other adults - say that the new regulations will have devastating consequences for them.

At the high court today, Mr Justice Mitting ruled that the claimants’ desire for a judicial review before the policy's inception on April 1 was too short a timescale.

But he said a full hearing could proceed in May if he decided that a review should go ahead after hearing the Department of Work and Pensions' reasons for contesting the challenge.

During today's hearing, IDS's representative, Edward Brown, argued that the claimants could make use of Discretionary Housing Payments (DHPs) to fill the void left by the bedroom tax.

However, Justice Mitting referred to a National Housing Federation report that claimed DHPs will not cover the losses disabled tenants can expect to make under the new policy.

Rebekah Carrier, the solicitor acting for the claimant children and their parents, said: “These changes will have a catastrophic impact on our clients and many thousands more vulnerable children and adults. Experts have assessed my clients as being unable to share a room with their siblings. A year ago the Children’s Commissioner warned the government that these changes would have a disproportionate and devastating impact on families with disabled children and those fleeing domestic violence. The appalling situation my clients now find themselves in was entirely predictable and avoidable.

"The government is advising these families to consider taking in a lodger to make up the financial shortfall, but this is a ludicrous suggestion. None of these families have a spare room available because the rooms are already being used. It is also very surprising that the government is advising families with disabled children, and children suffering trauma following serious abuse, to invite a stranger into their home.”

The claims are supported by the charities the National Autistic Society and Contact a Family. Both charities have submitted witness evidence in support of the claims.