Work and Pensions Secretary Iain Duncan Smith has said that housing benefit changes that have been introduced today are about "fairness".
In response to criticisms of the so-called 'bedroom tax', he said: "The reality is this is about getting our housing benefit back into order".
"This is about fairness. It's about fairness to those who pay vast sums of money in taxation to see that people living in subsidised accommodation who often don't use the bedrooms they've got, while others in overcrowded accommodation.... they can't get the accommodation they need.
"This is a nonsense problem that was created by the last government who didn't build enough housing and didn't manage the housing stock properly".
George Osborne has accused the Government's welfare reform critics of talking "ill-informed rubbish."
Find out more about the raft of changes to the welfare benefits system that began to come into force from the 1 April.
The government has been forced to defend its changes to the benefits system after prominent church leaders claimed they were 'unjust'.