Work and Pensions Secretary Iain Duncan Smith recently insisted "There is no bedroom tax' during an appearance on BBC1's The Andrew Marr Show.
He explained: "This is about under-occupancy, let's be very clear about what this is about. We have in social sector housing, a very large number of people in houses where they have many more bedrooms than they actually need.
"Something like a million spare bedrooms are sitting around. Meanwhile, there are a quarter of a million people in overcrowding and a million people on the waiting list trying to get into housing."
Mr Duncan-Smith said the government wants people who are under occupying their homes to move to smaller properties or pay more.
"What we're saying to them is you can stay where you are, but if you do you'll have to pay more. Exactly the same people in the same criteria who rent under in the private sector and get housing benefit are not allowed to have extra bedrooms".