The new cap on family benefits will encourage "responsibility" about the number of children people have, a cabinet minister has said.
Culture Secretary Jeremy Hunt told BBC Two's Newsnight that the state should not support families who get more in benefits than the average family earns.
But Mr Hunt said a ceiling of about £26,000 per household in benefits was not a "penalty" on large families.
However, Labour leader Ed Miliband accused him of "lecturing" people.
Chancellor George Osborne unveiled proposals on Monday for a maximum limit on the amount of benefits a family can claim from 2013.
An estimated 50,000 households may be affected.
Mr Hunt said that, with the exception of the disabled, no family would receive more in benefits than the average family got from going out to work.
"The number of children that you have is a choice and what we're saying is that if people are living on benefits then they make choices but they also have to have responsibility for those choices," he said.
"It's not going to be the role of the state to finance those choices."
Mr Hunt added: "You can have children but if you are going to ask for support that is more than the average wage that people earn then we're saying no, the state shouldn't support that.
"That's not fair on working people who have to pay the taxes to pay those benefits."
The minister also said it was right to withdraw previously universal child benefit from families where one parent was paying the higher rate of income tax.
He said: "If ever there was a week when the Conservative Party and the coalition demonstrated its commitment to fairness, it's this week when they removed child benefit from top-rate taxpayers."
However, Mr Miliband told ITV1's This Morning the child benefit announcement been a "complete shambles", which had caused "huge anxiety".
He added: "And I think we need to support all families in this country and certainly not lecture them in the way that Jeremy Hunt sounds like he's doing."
Sally Copley of Save the Children said: "Politicians should be focusing on how they are going to meet the target to end child poverty in the UK by 2020 rather than perpetuating the myth of the 'undeserving poor'.
"Children are the ones who'll end up suffering if a parent suddenly loses their job because of the economic crisis, or if their mum or dad becomes a single parent."
Donald Hirsch, from the Loughborough University's Centre for Research in Social Policy told BBC Radio 4's Today programme statements such as Mr Hunt's marked "quite a slippery slope".
"It's a real simplification to divide people effectively into these undeserving poor or lifetime poor who we say 'these are the choices you make and if you make them we're not going to support you', and people who are working.
"In the present system we do expect people to go out and look for work if they can and if they lose their jobs we think about their needs, not just some crude comparison with someone who is working on an average wage."