In a move that threatens to reopen the row with the Archbishop of Canterbury over the morality of Coalition policy, the Prime Minister suggested it was wrong for the work shy to expect the taxpayer to fund their lifestyles without limit.
Speaking on ITV's This Morning programme he said he wanted to change the 'values' of the nation to reverse the dependency culture.
He said: 'The biggest change I want to make as Prime Minister is to change the values where if people do the right thing, work hard and try to support their families we reward them and if people do the wrong thing they get punished.'
And he said he shared the frustration of hard-working families who complain others have children they cannot afford, knowing the taxpayer will foot the bill.
Official figures show almost 100,000 of those on benefits have four or more children, with more than 900 claimants having at least eight.
In many cases the claimants are entitled to a large council house as well as hefty benefit payments.
Mr Cameron stressed ministers are capping the amount of benefits a family can receive at £25,000 a year.
He added: 'Should we do more to help people who want to work hard and do the right thing? Yes.
'I get people saying, "We waited before we got married until we could afford it, we waited till we could afford to have children, we waited and then we managed to get a house and I see someone down the road do none of those responsible things and they get put up in a council house, they have as many children as they want. They're not thinking like I'm thinking".'
His comments came just 24 hours after the Archbishop of Canterbury lambasted the Coalition's welfare policies.
Dr Rowan Williams accused ministers of presiding over a 'quiet resurgence of the seductive language of "deserving" and "undeserving" poor' – a claim that was angrily denied.
Mr Cameron's intervention echoes comments by the Culture Secretary Jeremy Hunt, who provoked a storm last year by suggesting the jobless should stop having children they can't afford.
A Labour spokesman retorted: 'Today we have the Prime Minister lecturing people about whether they can afford to have children. The Government should concentrate on creating jobs and not cutting too far and too fast.
'It's creating a vicious circle in our economy which is really hitting families.'
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