Iain Duncan Smith tonight hit back at claims by senior religious figures that government welfare reforms would hit children hardest, insisting there was "nothing moral" about leaving families on benefits.
In the face of a searing attack led by the new Archbishop of Canterbury in his first major political intervention, the Work and Pensions Secretary said "fairness" was at the centre of the overhaul he was steering through parliament.
A letter in the Sunday Telegraph signed by 43 bishops and endorsed by the Archbishops of Canterbury and York claimed that capping benefit rises at 1% will have a "deeply disproportionate" effect on children.
But Mr Duncan Smith told ITV News: "This is about fairness. People who are paying taxes, working very hard, have hardly seen any increases in their salary and yet, under the last government, the welfare bill rose by some 60% to £200 billion. That means they have to pay for that under their taxes, which is simply not fair.
"That same system trapped huge numbers, millions, in dependency, dependent on the state, unable, unwilling to work.
"What is either moral or fair about that? That's my challenge over to the bishop."
He added: "There is nothing moral or fair about a system that I inherited that trapped people in welfare dependency, some one in every five households has no work, that's not the way to end child poverty.
"Getting people back to work is the way to end child poverty. That's the moral and fair way to do it."
But the Most Rev Justin Welby, who will be formally enthroned at Canterbury Cathedral on March 21, told the Sunday Telegraph that "children and families will pay the price" if plans to change the system go ahead in their current form.
The archbishop said the Welfare Benefits Up-rating Bill would remove the protection given to families against the rising cost of living and could push 200,000 children into poverty.
"As a civilised society, we have a duty to support those among us who are vulnerable and in need. When times are hard, that duty should be felt more than ever, not disappear or diminish," he said.
"It is essential that we have a welfare system that responds to need and recognises the rising costs of food, fuel and housing.
"The current benefits system does that, by ensuring that the support struggling families receive rises with inflation.
"These changes will mean it is children and families who will pay the price for high inflation, rather than the Government."
He added: "Politicians have a clear choice. By protecting children from the effects of this Bill, they can help fulfil their commitment to end child poverty."
Liberal Democrat peer Lord Ashdown said the Archbishop of Canterbury's comments were "an important thing" for him to say and insisted "all of us are concerned about" it.
Shadow home secretary Yvette Cooper said: "I think it is pretty simple on Mother's Day to say that the Government should help mums not millionaires - they are cutting taxes for millionaires and yet they are taking away money from mums at a time when they really want to be able to stay at home with their new-borns."