Deputy Prime Minister Nick Clegg has defended planned cuts to housing benefit after Labour accused the government of "threatening people's homes".
He said the changes, announced in the Spending Review, were "fair".
And it was not fair that people who went out to work got less help with accommodation than those who did not.
But Labour said the changes would penalise the long-term unemployed who were genuinely seeking work.
Shadow Work and Pensions Secretary Douglas Alexander said: "How can it be right that somebody who's on Jobseekers Allowance, has spent a year looking for a job, turning up for interviews, arbitrarily on a timetable set by this coalition, is going to lose 10% of their housing benefit after one year.
"We wanted to make sure that if you're long-term unemployed you were guaranteed a job.
"We seem to be in a position now where after a year this Conservative government is threatening people's homes."
Mr Alexander also said he backed "in principle" the coalition's plan to replace all out-of-work benefits with a single "universal credit" payment.
He said such a move was "sensible" but he would be scrutinizing the government "very carefully" over its £2bn start-up costs.
The government's plans to give local authorities control of council tax benefit were making the system "more complex" already, he added.
In its spending review last week, the government announced a 10% cut to the housing benefit budget, with cuts for the long-term unemployed and single people under 35 only able to claim it for a room rather than a whole property.
At the same time, the government is cutting the money it spends on new social housing by 50% - but hopes to make up the shortfall by allowing housing associations to charge close to the full market rate for rent.
The move means new tenants may have to pay as much as three times as much as existing ones to live in a council house.
The National Housing Federation, which represents English housing associations, has said the average rent for a three-bedroom council home could go up from £85 to £250 a week.
Existing tenants will not be affected but the changes mean new tenants are likely to be dependant on housing benefit to cover the extra cost, which the NHF says is likely to act as a "powerful disincentive" for the unemployed to get a job.
But Mr Clegg told the BBC's Andrew Marr show the plans would create more social housing and were "fair" on housing benefit claimants.
He said: "We need to do something about a housing benefit bill which has gone up from £10bn to £21bn in recent years under Labour and there haven't been enough affordable homes built.
"What we are trying to do is, instead of simply repeating the mistakes of the past, make it fairer, so people get the housing benefit they need but not in excess of what people would get if they work, and at the same time provide an incentive for people to build, by our estimate, around 400,000 new affordable homes over the next decade."
Mr Clegg has also told how he searched his conscience over the coalition's spending cuts.
Appearing on BBC Radio 4's Desert Island Discs, he said there were no "pain-free alternatives" but he found that putting through the measures was "morally difficult".