Britain's four Children's Commissioners say the government's Welfare Reform Bill will cause significant harm young people.
In a joint statement, they explained why they were concerned at the "serious negative impact" the bill could have on children.
The Commisioners declared: "We urge the UK Government to reconsider its plans, specifically the £26,000 benefit cap to be imposed on families each year."
They pointed out that the cap is likely to lead to more families becoming homeless and breach UN child rights rules. Their statement also warned of the knock-on effect the changes are likely to have on council and charity services.
The statement continued: "We are concerned that many more families and their children will be pushed into absolute poverty over the coming years if these proposed changes go ahead."
The Commissioners also said that children have rights independent of their parents, and under the UN Convention on the Rights of the Child, children's rights must be considered in the drafting of legislation that affects them.
Scottish Commissioner Tom Baillie told The Herald newspaper in Glasgow that children with disabilities were already three times more likely to be living in poverty and were just one of the groups likely to be further impoverished by measures in the bill.
He added: "What the Government doesn't recognise is that a modest loss of income for a family already living in difficult circumstances can have a significant impact, quite disproportionate to the actual amounts involved. This is absolutely unacceptable and it also sets the Government way back in terms of the target of eradicating child poverty by 2020 – which may become impossible."