The husband of a disabled woman who is challenging the controversial so-called "bedroom tax" at the UK's highest court has described the "heartache" they have suffered following changes to housing benefit regulations.
As a group of protesters chanted "axe the bedroom tax" outside the Supreme Court in London on Monday, Jayson Carmichael, who is full-time carer for wife Jacqueline, spoke of their hopes that there would finally be a ruling in their favour.
Mr Carmichael, 53, from Southport, Merseyside, said: "It has caused us a lot of stress and heartache. We are having to think about it all the time and being depressed about it. It is fight after fight, case after case."
Over a three-day hearing a panel of seven Supreme Court justices, headed by the court's president Lord Neuberger, will tackle the question of whether vulnerable members of society are being discriminated against.
Campaigners say the regulations, introduced in April 2013, have had a ''devastating'' impact, and argue that they "unjustifiably" discriminate against the disabled.
The challenge brought by 43-year-old spina bifida sufferer Mrs Carmichael, who shares a two-bedroom housing association flat with her husband, is one of five appeals by people who have so far suffered defeat at both the High Court and Court of Appeal.
As well as hearing the cases of Mrs Carmichael and the four others, who are either disabled or carers, the judges are being asked to rule on a challenge by the Government a gainst recent findings of the Court of Appeal in favour of a victim of domestic violence and the family of a severely disabled teenager.
Last month, appeal judges declared that a woman referred to as "A", who lives in a council house fitted with a secure panic room to protect her from a violent ex-partner, and Paul and Sue Rutherford, from Pembrokeshire, who look after 15-year-old grandson Warren, had "suffered discrimination", contrary to Article 14 of the European Convention on Human Rights (ECHR).
The Court of Appeal found that the discrimination had not been "justified" by Work and Pensions Secretary Iain Duncan Smith.
But in 2014, the Court of Appeal ruled against Mrs Carmichael and the others, who complain that the regulations unlawfully discriminate against people with disabilities who have a need for an additional bedroom because of that disability.
In that ruling, Master of the Rolls Lord Dyson said the court could only intervene if measures were "manifestly without reasonable foundation" - and that test was not satisfied. The Secretary of State had "justified the discriminatory effect of the policy".
The others who have appeals before the Supreme Court following the 2014 decision are widower Richard Rourke, from Derbyshire, who uses a wheelchair; James Daly, from Stoke, who has a severely-disabled 13-year-old son; single Mervyn Drage, 59, from Manchester, who suffers from both mental and physical health problems, and a mother who can only be referred to as "JD" to protect the identity of her disabled adult daughter.
The recent successful action brought by single mother A concerned the effect of the regulations on women living in Sanctuary Scheme homes which have been specially adapted because of risks to the women and children who live in them. The other, brought by the Rutherfords, involved the impact on seriously disabled children who need overnight care.
The Government rejects the term ''bedroom tax'' and says the regulations remove what is in fact a ''spare room subsidy'', with the aim of encouraging people to move to smaller properties and save around £480 million a year from the housing benefit bill.
A DWP spokesman said in a statement before the start of the latest round of the litigation: " Removing the spare room subsidy has restored fairness to the system for claimants as well as the taxpayer, and the numbers subject to a reduction are falling.
"We know that there are cases where people may need extra support - but rather than put in place complex exemptions, we have given local councils the freedom to decide what is best for their communities.
"That's why we have given councils £500m of funding to provide discretionary payments to those that need them, with a further £870m to be provided up to 2020."
The hearing continues on Tuesday.