Universal child benefit should be abolished and tax credits used instead to bolster the income solely of poor families, says the head of Barnardo's children's charity.
Martin Narey, chief executive of Barnardo's, says in an article for the Guardian newspaper that the case for removing welfare benefits from the rich and middle class is now "morally overwhelming".
He says that limiting the payments to poorer people only, could make £5.1 billion available for crucial assistance to the most vulnerable, rather than those who are already well off.
The comments come as the Conservative Party meets for its annual conference in Birmingham, and the coalition government discusses a radical overhaul of the tax and benefit system.
Frank Field, the Labour MP who is leading a review into poverty for the government, has suggested saving £3 billion by limiting child benefit to children under 13, rather than 18.
Martin Narey rejects this argument, saying that under such an arrangement poor families would lose "nearly £2,000 a year. At the same time, David Cameron would continue to receive £47 a week in child benefit to add to his salary of around £150,000".
The Barnardo's chief says that the government must reform child benefit so that only the most needy receive benefit, because "children growing up in poor households still have poor outcomes. This perpetuates the cycle of disadvantage to the next generation."
The charity says much more money has to be found for those at the bottom of society because of the impact of the recession and draconian coalition government welfare cuts.
An extra £4.7 billion is needed to meet the goal of halving the number of youngsters living in poverty to 1.7 million this year, Barnado's CEO says.
He asks: "Do those of us who are better off have the decency and bravery to give up this bounty to protect the poorest and most vulnerable?"
The proposal is likely to be highly controversial.
For many years, anti-poverty campaigners have argued that universal benefits are far more effective at channelling money to the poorest because of the low take-up rate of means tested benefits.
Attempts to merge tax and benefit databases might change the argument, but are fraught with technical difficulties.
Baranado's (http://www.barnardos.org.uk/) is Britain's largest children's charity.
More from The Guardian here: http://www.guardian.co.uk/politics/welfare