The controversial so-called "bedroom tax" will be under the spotlight next month at the UK's highest court.
Supreme Court justices are to tackle the question of whether vulnerable members of society are discriminated against during a three-day hearing in London.
A panel of seven judges, headed by the Supreme Court president Lord Neuberger, will hear argument in a number of appeals resulting from legal rulings over changes to housing benefit regulations.
One of the cases to be decided is the Government's challenge against the Court of Appeal's findings on Wednesday in favour of a victim of domestic violence and the family of a severely disabled teenager.
Another relates to an earlier decision by Court of Appeal judges relating to a complaint by a number of appellants that the regulations unlawfully discriminate against people with disabilities who have a need for an additional bedroom because of that disability.
The High Court dismissed their application for judicial review and their later challenge against that decision was rejected by appeal judges in February 2014.
On Wednesday, 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).
After announcing that the discrimination had not been "justified" by the Government, the judges said they were granting Work and Pensions Secretary Iain Duncan Smith permission to appeal to the Supreme Court.
The Supreme Court said on Thursday that the Government's appeal in the cases of A and the Rutherfords has now been listed to be heard alongside other "bedroom tax" challenges, starting on Monday February 29.
The 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 millions of pounds from the housing benefit bill.
In the 2014 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".
At the conclusion of the latest ruling, Lord Thomas said no arguments had been addressed to the court during the proceedings relating to A and the Rutherfords "to the effect that the scheme as a whole, comprising housing benefit and Discretionary Housing Payments (DHPs) is not discriminatory in its overall effect".
He added: "We have no doubt that such arguments will be addressed to the Supreme Court."
Campaigners say the regulations have had a ''devastating'' impact on many vulnerable people.
Shadow work and pensions secretary Owen Smith said: "It is extraordinary that the Tories are going to take this case to the Supreme Court, in a bid to maintain an indefensible policy.
"Just the Supreme Court session itself will cost the Government more in legal fees than £200,000 needed to exempt all of the victims of domestic abuse affected by this ruling.
"If the Tories had an ounce of decency, at the very least they would have responded to the Court of Appeal's decision by exempting families of disabled children and victims of domestic violence from the Bedroom Tax.
"Instead they are instructing a team of expensive lawyers to fight in the Supreme Court for the right to drive people further in to poverty."