The secretary of state for work and pensions, Iain Duncan Smith, unsuccessfully argued that the claim should be dismissed. Mr Justice King rejected the secretary of state’s arguments, granted permission to the claimants and ordered that the hearing must take place no later than 30th October this year.

The High Court’s Order comes shortly after the Supreme Court ruled that the benefit cap breaches the rights of children, meaning that they are not provided with “adequate food, clothing, warmth and housing, the basic necessities of life” (Lord Kerr).

Last year the UK government also conceded that the cap had “unintended consequences” for victims of domestic violence living in women’s refuges, and so amended the regulations to remove women’s refuges from the cap.

Now the High Court will examine whether the cap also breaches the rights of disabled people and their carers. The High Court’s Order also comes at a time when the government in the Queen’s Speech has made clear its intention to cut the cap even further.

The claim is brought by two families – in both, an adult relative is providing full time care to their elderly and disabled grandmothers. They are able to perform their caring roles only with the support of state benefits, covering their housing and living expenses, and both are in receipt of Carers’ Allowance.

The families argue that the benefit cap is unfair and unlawful because of its impact on carers and those who they care for. Included in the group of families who are capped are those who receive Carer’s Allowance. To qualify for Carer’s Allowance the benefit claimant has to be providing full time care - upwards of 35 hours a week – to a severely disabled person who receives Disability Living Allowance (DLA). This means that anyone receiving Carer’s Allowance is by definition not available to work, because they must be providing care. The Secretary of State has provided an exemption from the cap to those who receive DLA – but not to their carers. Two categories of carer only are exempt: carers for children or spouses. Any carer who provides care to another adult, such as a parent or grandparent, is caught by the cap.

One of the claimants, Ashley Hurley, is a young woman who was brought up by her grandmother and who is committed to providing her with the care and support which she needs.

She has said: “I had understood that the benefit cap was meant to encourage people to work and to address the problem of children growing up in workless families. I do not understand why it should apply to me as I do work, looking after my grandmother. If I did not care for my grandmother, then I suppose that we would have to ask the council to pay for care for her.

“It would certainly cost the state more to pay someone to provide the care that I provide, and my grandmother would be very distressed about having care provided by strangers. Indeed, I expect that both her mental and physical health would rapidly deteriorate if this happened. I do not feel that I would be able to allow this to happen, and I do not understand why the government would think it was better for the State to care for my grandmother instead of her own family.”

The solicitor for the families, Rebekah Carrier, said: “My clients have been hit by the benefit cap because they are disabled or they provide essential care to their disabled relatives. They are not skivers – they are strivers. They provide full time care and save the state money. The government seeks to justify the cap by the financial savings achieved but the long term consequences of this arbitrary benefit cap are likely to have not only devastating consequences for individual disabled people and those who care for them, but serious financial costs.

“If Ashley Hurley is forced into stopping her work as a carer, the state will have to pick up the tab and arrange alternative care. This is not a fair or sensible policy.

“The Supreme Court has already ruled that the benefit cap breaches international protections for the rights of children. Now the High Court has allowed this claim to proceed, considering whether it also breaches the rights of disabled people and their carers. The government must halt this policy which simply hits vulnerable people.”