Government cuts to benefits have been condemned in a letter signed by 43 bishops in the Church of England.
The letter, published in The Telegraph, says that the welfare reforms will have a "deeply disproportionate impact on families with children".
The warning comes ahead of a debate in the House of Lords this week on the Welfare Benefits Up-rating Bill,
The bishops said it was "unacceptable" of the Government to transfer the risk of high inflation rates from the Treasury to families and children.
Changes to benefits mean families will have no protection against rising prices, with as many as 200,000 children at risk of being pushed into poverty, they warn.
"The change will hit the poorest the hardest. About 60 per cent of the savings from the uprating cap will come from the poorest third of households. Only 3 per cent will come from the wealthiest third," the bishops said.
The Archbishop of Canterbury, Justin Welby, is supporting their campaign.
He said: "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.
"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."